A drilling-while-drilling light hydrocarbon separation apparatus and method

Abstract

The application discloses a drilling light hydrocarbon separation device and method, and belongs to the technical field of light hydrocarbon separation. The drilling light hydrocarbon separation device provided by the application takes a separation cylinder as a core space for light hydrocarbon separation, and the inner cavity of the separation cylinder receives drilling fluid through a feeding pipe. A pipeline heater externally heats the feeding pipe, so that light hydrocarbon is prevented from being liquefied due to temperature reduction in the conveying process. Through a controller, three parameters, i.e., real-time temperature of drilling fluid, real-time flow of drilling fluid and real-time pressure in the separation cylinder, are comprehensively used to dynamically adjust a gas extraction and pressure regulating component, so that the pressure in the separation cylinder is always lower than the critical gasification pressure of light hydrocarbon corresponding to the current temperature, light hydrocarbon is forced to keep in a gaseous state, the gaseous stability of light hydrocarbon is maintained from the perspective of thermodynamic phase equilibrium, reliable gaseous samples are provided for subsequent FID detection, and the accuracy of detection results is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of light hydrocarbon separation, in particular to a light hydrocarbon separation device and method while drilling. BACKGROUND

[0002] In the field of oil exploration and development, accurate identification and evaluation of oil and gas reservoirs are the core prerequisite for efficient resource exploitation. Among them, light hydrocarbon, as a key geochemical index reflecting the properties of reservoir fluid and oil and gas bearing capacity, occupies an irreplaceable position in water flooded layer evaluation, oil and gas migration path analysis and original oil and gas potential evaluation. Its molecular composition and content characteristics directly provide important basis for development plan.

[0003] Currently, the detection of light hydrocarbon in drilling fluid during drilling relies on the cooperation of drilling fluid degassing device and hydrogen flame ionization detector (FID), but the unique physical and chemical properties of light hydrocarbon make the detection face serious challenges. Light hydrocarbon is mostly liquid at normal temperature and pressure, and only changes into gas state when reaching a certain gasification temperature. In drilling operation, reservoir light hydrocarbon gasifies instantaneously due to the release of formation pressure, and condenses into liquid state during the process of returning to the ground with drilling fluid due to the low surface temperature being lower than the gasification critical condition, and uniformly disperses or dissolves in the drilling fluid system.

[0004] The existing conventional drilling fluid degassing device (such as vacuum degasser, electric degasser, etc.) is mainly designed for light components that can be gasified at normal temperature, and its degassing principle cannot break the phase balance of liquid light hydrocarbon and drilling fluid, resulting in that most of the liquid light hydrocarbon cannot be effectively separated. Even if a small amount of light hydrocarbon is separated by increasing the vacuum degree and increasing the stirring intensity, the separated light hydrocarbon will liquefy again in a short time because the environmental temperature after leaving the reservoir is continuously lower than the gasification condition. FID needs to rely on the signal generated by the ionization of gaseous light hydrocarbon in hydrogen flame for quantitative detection, and the existence of liquid light hydrocarbon will cause the detection signal to fluctuate sharply or even completely distorted.

[0005] The above technical bottleneck causes the deviation between light hydrocarbon analysis data and the real situation of the reservoir: the low content detection result may misjudge the high oil and gas reservoir as a water layer, and the abnormally high data may misjudge the weak water flooded layer as an oil and gas rich layer. This misinterpretation and evaluation error not only leads to the misjudgment of oil and gas layer, but also misleads the development decision, causing problems such as invalid drilling and design error of production capacity, which seriously restricts the effective use of oil and gas resources and the improvement of recovery rate, and becomes a key technical obstacle to fine exploration and efficient development.

[0006] Therefore, how to maintain the gaseous state of light hydrocarbon in drilling fluid to realize accurate detection by FID has become a technical problem to be solved by the technical personnel in the field. SUMMARY

[0007] The present application aims to provide a drilling light hydrocarbon separation device and method to overcome the problem of inaccurate detection results of the hydrogen flame ionization detector due to the presence of liquid light hydrocarbons in the prior art.

[0008] The present application solves the above technical problems by the following technical solutions:

[0009] The present application provides a drilling light hydrocarbon separation device, comprising a separation cylinder, an air extraction pressure regulating assembly, a feeding hose, a feeding pipe, a pipeline heater and a controller; the top of the separation cylinder is provided with a top cover, the outlet of the air extraction pressure regulating assembly communicates with the inner cavity of the separation cylinder through the top cover, a constant flow pump is arranged on the feeding hose for controlling the constant flow rate of the drilling fluid, the output end of the feeding hose is connected to the input end of the feeding pipe, the output end of the feeding pipe communicates with the inner cavity of the separation cylinder through the side wall of the separation cylinder for conveying the drilling fluid into the inner cavity of the separation cylinder; the pipeline heater is sleeved on the outer wall of the feeding hose for constant temperature heating of the drilling fluid in the feeding hose; a temperature sensor is arranged on the pipeline heater for obtaining the real-time temperature T of the drilling fluid; a flow sensor is arranged on the constant flow pump for obtaining the real-time flow rate Q of the drilling fluid conveyed into the separation cylinder per unit time; a pressure sensor is arranged in the separation cylinder for obtaining the real-time pressure in the separation cylinder ; the temperature sensor, the flow sensor and the pressure sensor are electrically connected to the controller, and the controller is electrically connected to the air extraction pressure regulating assembly for adjusting the air extraction pressure regulating assembly according to the obtained real-time temperature T of the drilling fluid, the real-time flow rate Q of the drilling fluid and the real-time pressure in the separation cylinder to maintain the light hydrocarbon in the drilling fluid in a gaseous state.

[0010] Further improvement of the present application is that the air extraction pressure regulating assembly comprises a vacuum pump and an electronic vacuum regulating valve, the output end of the vacuum pump is connected to the input end of the electronic vacuum regulating valve through an air pipe, and the output end of the electronic vacuum regulating valve serves as the outlet of the air extraction pressure regulating assembly.

[0011] Further improvement of the present application is that the pressure sensor is a plurality of distributed pressure sensors, and the plurality of distributed pressure sensors are vertically arranged at equal intervals in the separation cylinder; the real-time pressure in the separation cylinder is equal to the average value of all the distributed pressure sensors.

[0012] Further improvement of the present application is that it further comprises a support frame fixedly installed on the ground, a top plate fixedly installed at the top end of the support frame, and the separation cylinder is located in the cavity of the support frame and fixedly installed at the bottom end of the top plate.

[0013] Further improvement of the present application is that it further comprises a top hat and a plurality of support columns; the feeding pipe is horizontally arranged in an S shape, the plurality of support columns are fixedly arranged on the output end of the feeding pipe in a ring array, and the top hat is fixedly connected to one end of the plurality of support columns away from the feeding pipe.

[0014] The further improvement of the present application is that an annular separation groove is arranged in the cavity of the separation cylinder, the separation groove is sleeved on the output end of the feeding pipe and is in a horizontal state, the separation groove is used for conveying the drilling fluid to the separation groove through the feeding pipe, the fixed rods are fixedly connected between the outer wall surface of the separation groove and the inner wall surface of the separation cylinder, and the groove bottom of the separation groove is provided with a plurality of circular holes which are distributed at equal intervals.

[0015] The further improvement of the present application is that the device further comprises a driving motor, a circular plate and a rotating part, the rotating part comprises a rotating shaft, a separation plate, a separation block and a plurality of supporting arms.

[0016] The circular plate is arranged at the bottom of the top cover, the driving motor is arranged at the upper end surface of the top cover, the output end of the driving motor penetrates through the top cover and is transmissionally connected with the circular plate, one end of each supporting arm is fixedly connected with the bottom of the circular plate at intervals, the other end of each supporting arm is fixedly connected with the separation block, the lower part of the separation block is provided with the horizontally penetrating rotating shaft, the two ends of the rotating shaft are provided with the separation plates, and the separation plates are used for accelerating the gas release of the drilling fluid in the separation groove.

[0017] The further improvement of the present application is that the cross section of the separation block is Y-shaped, and the cross section of the separation plate is triangular.

[0018] The present application also provides a drilling light hydrocarbon separation method, which adopts the drilling light hydrocarbon separation device, and comprises the following steps.

[0019] S1, obtaining the real-time temperature T of the drilling fluid, the real-time flow Q of the drilling fluid and the real-time pressure in the separation cylinder ;

[0020] S2, based on the obtained real-time temperature T of the drilling fluid and the real-time flow Q of the drilling fluid, the target pressure of the separation cylinder is calculated , and the specific process is as follows:

[0021]

[0022] Wherein, A is a temperature coefficient, B is a flow coefficient, and C is a basic pressure constant.

[0023] S3, based on the target pressure of the separation cylinder and the real-time pressure in the separation cylinder , the pressure deviation is calculated, whether the pressure deviation is less than or equal to the preset threshold value is judged, if the judgment result is yes, the current state is maintained, if the judgment structure is no, the pressure in the separation cylinder is adjusted through the air extraction pressure regulating assembly, and the step S1 is returned.

[0024] The further improvement of the present application is that the step S2 can be replaced by the following steps:

[0025] The light hydrocarbon critical gasification pressure corresponding to the current drilling fluid real-time temperature T is calculated through the virtual critical pressure formula ; based on the obtained drilling fluid real-time temperature T, drilling fluid real-time flow Q, the target pressure of the separation cylinder is calculated , specifically:

[0026]

[0027] Wherein, A is the temperature coefficient; B is the flow coefficient; C is the base pressure constant;

[0028] determine whether it is less than or equal to If the result is no, it is corrected and returns to step S1; if the result is yes, step S3 is executed;

[0029] The correction is specifically: reducing the temperature of the pipe heater or enhancing the pumping strength of the air pumping pressure regulating assembly.

[0030] Compared with the prior art, the positive progress effect of the present application is:

[0031] The drilling light hydrocarbon separation device provided by the present application takes the separation cylinder as the core space for light hydrocarbon separation, and its inner cavity receives drilling fluid through the feed pipe; the pipe heater externally heats the feed pipe to avoid the liquefaction of light hydrocarbon in the drilling fluid during the conveying process due to temperature reduction; the temperature sensor monitors the temperature of the heated drilling fluid in real time to ensure that the critical temperature of light hydrocarbon gasification is reached; the constant flow pump is arranged to realize accurate control of the flow rate of the drilling fluid, so as to avoid the change of the phase state of light hydrocarbon caused by flow rate fluctuation; the flow sensor feeds back the flow rate of the drilling fluid in real time; the pressure sensor feeds back the pressure state in the separation cylinder in real time; the controller dynamically adjusts the air pumping pressure regulating assembly based on the three parameters of the real-time temperature of the drilling fluid, the real-time flow of the drilling fluid and the real-time pressure in the separation cylinder, and controls the suction and pressure balance to keep the pressure in the separation cylinder always lower than the critical gasification pressure of light hydrocarbon corresponding to the current temperature, so as to force the light hydrocarbon to remain in a gaseous state, maintain the gaseous stability of light hydrocarbon from the perspective of thermodynamic phase equilibrium, provide reliable gaseous samples for subsequent FID detection, and improve the accuracy of the detection result. BRIEF DESCRIPTION OF DRAWINGS

[0032] The accompanying drawings for the specification are used to provide a further understanding of the present application, and form a part of the present application. The schematic embodiments of the present application and their descriptions are used to explain the present application, and do not constitute an improper limitation on the present application.

[0033] Figure 1 It is a front view of the drilling light hydrocarbon separation device of the present application.

[0034] Figure 2 It is a perspective structural schematic view of the drilling light hydrocarbon separation device of the present application.

[0035] Figure 3 It is a connection relationship schematic view of the separation cylinder in a specific embodiment of the present application.

[0036] Figure 4 The schematic diagram of the cavity structure of the separation cylinder in a specific embodiment of the present application.

[0037] Figure 5 The schematic diagram of the connection relationship between the feeding hose and the top cap in a specific embodiment of the present application.

[0038] Figure 6 The schematic diagram of the connection of the support arm in a specific embodiment of the present application.

[0039] Figure 7 The schematic diagram of the connection of the rotating part in a specific embodiment of the present application.

[0040] 1, support frame; 2, separation cylinder; 3, pipeline heater; 4, feeding pipe; 5, driving motor; 6, top plate; 7, constant flow pump; 8, vacuum pump; 9, electronic vacuum regulating valve; 10, top cap; 11, discharging port; 12, air pipe; 13, separation groove; 14, rotating part; 15, fixed rod; 16, top cap; 17, support column; 18, round plate; 19, support arm; 20, round hole; 21, separation block; 22, separation plate; 23, rotating shaft; 24, feeding hose. DETAILED DESCRIPTION

[0041] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. The components of the embodiments of the present application described and shown in the drawings can be arranged and designed in various different configurations.

[0042] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of the present application.

[0043] It should be noted that: similar numbers and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0044] In the description of the embodiments of the present application, it should be noted that if the terms "upper", "lower", "horizontal", "inner" and the like indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, or the orientation or position relationship when the product of the present application is usually placed, which is only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second" and the like are only used for differentiation and cannot be understood as indicating or implying relative importance.

[0045] In addition, it should be noted that unless otherwise explicitly specified and limited, if the terms "arrangement", "installation", "connection", "connection" appear, they should be understood in a broad sense, for example, they can be fixedly connected, or they can be detachably connected, or integrally connected; can be mechanically connected, or electrically connected; can be directly connected, or indirectly connected through an intermediate medium; can be connected inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0046] Noun explanation:

[0047] Light hydrocarbon: hydrocarbon with carbon atom number ≤8.

[0048] The present application will be further described in detail below in combination with the drawings and specific embodiments, which are an explanation of the present application rather than a limitation.

[0049] Reference Figure 1 , the present application provides a drilling light hydrocarbon separation device, including separation cylinder 2, suction pressure regulating assembly, feeding hose 24, feed pipe 4, pipeline heater 3 and controller; The top of the separation cylinder 2 is provided with a top cover 10, the outlet of the suction pressure regulating assembly passes through the top cover 10 and communicates with the inner cavity of the separation cylinder 2, the constant flow pump 7 is arranged on the feeding hose 24, which is used to control the constant flow rate of the drilling fluid, the output end of the feeding hose 24 is connected with the input end of the feed pipe 4, the output end of the feed pipe 4 passes through the side wall of the separation cylinder 2 and communicates with the inner cavity of the separation cylinder 2, which is used to deliver the drilling fluid to the inner cavity of the separation cylinder 2; The pipeline heater 3 is sleeved on the outer wall surface of the feeding hose 24, which is used to constant temperature heating of the drilling fluid in the feeding hose 24; The temperature sensor is arranged on the pipeline heater 3, which is used to acquire the real-time temperature T of the drilling fluid; The flow sensor is arranged on the constant flow pump 7, which is used to acquire the real-time flow Q of the drilling fluid delivered to the separation cylinder 2 per unit time; The pressure sensor is arranged in the separation cylinder 2, which is used to acquire the real-time pressure P in the separation cylinder 2 ; The temperature sensor, the flow sensor and the pressure sensor are electrically connected with the controller respectively, the controller is electrically connected with the suction pressure regulating assembly, which is used to control the constant flow rate of the drilling fluid to the separation cylinder 2 according to the acquired real-time temperature T of the drilling fluid, the real-time flow Q of the drilling fluid and the real-time pressure P in the separation cylinder 2 The gas extraction and pressure regulating assembly is adjusted to maintain the light hydrocarbon in the drilling fluid in a gaseous state.

[0050] In use, the pipeline heater 3 is turned on in advance, and then the constant flow pump 7 is started to sequentially convey the drilling fluid through the feeding hose 24, the feeding pipe 4 into the cavity of the separation cylinder 2, and the gas-liquid separation is performed through the separation cylinder 2 to release the gas in the drilling fluid; and the pressure in the cavity of the separation cylinder 2 is controlled through the gas extraction and pressure regulating assembly.

[0051] The drilling light hydrocarbon separation device provided by the application realizes the stable maintenance of light hydrocarbon in a gaseous state through the construction of a closed-loop control separation system. The separation cylinder 2 is the core space for light hydrocarbon separation, and its inner cavity receives the drilling fluid through the feeding pipe 4. The pipeline heater 3 externally heats the feeding pipe 4 to avoid the liquefaction of light hydrocarbon due to the temperature reduction in the conveying process. The temperature sensor monitors the temperature of the heated drilling fluid in real time to ensure that the critical temperature for the gasification of light hydrocarbon is reached. The constant flow pump 7 is arranged to realize the accurate control of the flow rate of the drilling fluid to avoid the phase state change of light hydrocarbon caused by the flow rate fluctuation. The flow sensor feeds back the flow rate of the drilling fluid in real time. The pressure sensor feeds back the pressure state in the separation cylinder 2 in real time. The controller dynamically adjusts the gas extraction and pressure regulating assembly by comprehensively considering the real-time temperature of the drilling fluid, the real-time flow rate of the drilling fluid and the real-time pressure in the separation cylinder. Through the suction and pressure balance control, the pressure in the separation cylinder 2 is always lower than the critical gasification pressure of light hydrocarbon corresponding to the current temperature, so that the light hydrocarbon is forced to remain in a gaseous state, and the stability of the light hydrocarbon in a gaseous state is maintained from the perspective of thermodynamic phase equilibrium, thereby providing a reliable gaseous sample for subsequent FID detection and improving the accuracy of the detection result.

[0052] Preferably, referring to Figure 2 and Figure 3 , the gas extraction and pressure regulating assembly comprises a vacuum pump 8 and an electronic vacuum regulating valve 9. The output end of the vacuum pump 8 is connected to the input end of the electronic vacuum regulating valve 9 through the air pipe 12, and the output end of the electronic vacuum regulating valve 9 serves as the outlet of the gas extraction and pressure regulating assembly.

[0053] A closed-loop pressure regulating system is constructed through the cooperation of the vacuum pump 8 and the electronic vacuum regulating valve 9. The vacuum pump 8 forms a gas extraction power source through the air pipe 12 to provide a basic vacuum environment for the separation cylinder 2. The electronic vacuum regulating valve 9 adjusts the valve opening in real time through electrical signals to accurately control the gas output, thereby achieving constant pressure. The series connection structure of the two enables the pressure in the separation cylinder 2 to be adjusted through the precise throttling action of the electronic vacuum regulating valve 9 under the condition that the vacuum pump 8 continuously operates. Through the high-precision closed-loop control of the pressure in the separation cylinder 2, it is ensured that the pressure value is always lower than the critical gasification pressure of light hydrocarbon at the current temperature, thereby maintaining the stable gasification state of light hydrocarbon.

[0054] Preferably, the pressure sensor is a plurality of distributed pressure sensors vertically and equidistantly arranged in the separation cylinder 2; the real-time pressure in the separation cylinder 2 is equal to the average value of all the distributed pressure sensors.

[0055] The spatial arrangement of the distributed pressure sensors and the data fusion strategy optimize the pressure monitoring accuracy. Arranging the pressure sensors as a plurality of distributed nodes vertically and equidistantly can cover the pressure gradient changes in different height regions of the separation cylinder 2 and eliminate the local pressure measurement errors caused by the installation position limitation of a single sensor. By calculating the average value of the pressures of all the distributed nodes as the real-time pressure value, the instantaneous pressure abnormalities caused by the flow disturbance of the drilling fluid and the fluctuation of the gas-liquid interface can be effectively suppressed, and a global pressure parameter closer to the real working condition can be obtained. This pressure parameter serves as the feedback signal of the closed-loop control system and provides a reliable basis for the accurate adjustment of the gas extraction and pressure regulation assembly, ensuring that the pressure in the separation cylinder 2 is stable above the critical gasification pressure of light hydrocarbons and guaranteeing the maintenance of light hydrocarbons in a gaseous state from the monitoring method level.

[0056] Preferably, referring to Figure 1 It also includes a support frame 1 fixedly installed on the ground, a top plate 6 fixedly installed at the top end of the support frame 1, and the separation cylinder 2 located in the cavity of the support frame 1 and fixed at the bottom end of the top plate 6.

[0057] The overall support structure is constructed to realize the stable fixation of the separation cylinder 2. The support frame 1 is fixedly installed on the ground to form the basic support frame of the device, avoiding the overall displacement caused by external forces during operation. The top plate 6 at the top end of the support frame 1 serves as a rigid connection platform to provide a high support point for the separation cylinder 2. By fixing the separation cylinder 2 at the bottom end of the top plate 6, it is suspended in the cavity of the support frame 1, which not only ensures the safe distance between the separation cylinder 2 and the ground but also suppresses the vibration of the separation cylinder 2 during the gas extraction and pressure regulation process through the rigid connection of the top plate 6 and the support frame 1. The layout of the separation cylinder 2 in the cavity of the support frame 1 further restricts the horizontal displacement of the separation cylinder 2 by utilizing the lateral structure of the support frame 1, forming a three-dimensional spatial constraint. The above-mentioned structures work together to ensure that the separation cylinder 2 is in a stable spatial position and attitude during the separation of light hydrocarbons, avoiding the fluctuation of the phase state of light hydrocarbons caused by mechanical vibration or displacement, thereby guaranteeing the continuous and stable separation and detection of gaseous light hydrocarbons.

[0058] Preferably, referring to Figure 5 It also includes a top hat 16 and a plurality of support columns 17. The feed pipe 4 is in a horizontal S shape, and the plurality of support columns 17 are fixed in a ring array on the output end of the feed pipe 4. The top hat 16 is fixedly connected to the end of the plurality of support columns 17 away from the feed pipe 4.

[0059] ​The horizontally placed S-shaped feeding pipe 4 prolongs the drilling fluid flow path, so that the fluid can obtain more sufficient heat exchange under the action of the pipe heater 3, and ensure temperature uniformity; the connection structure of the feeding hose 24 and the feeding pipe 4 enhances the system flexibility, and reduces the influence of vibration on flow rate; the annular array of support columns 17 is fixed at the output end of the feeding pipe 4 to form a stable support structure, and the top cap 16 is covered on the end of the support column 17 in a multi-point connection mode, which effectively disperses the fluid impact force, prevents the high-speed flowing drilling fluid from directly impacting the inner wall of the separation cylinder 2 to cause liquid droplet splashing, and at the same time avoids the pressure jump to destroy the stable state of the gasified light hydrocarbon, and the synergistic effect of each component forms a triple protection mechanism of flow rate control-temperature maintenance-pressure buffering, which creates a stable environment for the light hydrocarbon to continuously maintain a gaseous state.

[0060] Preferably, referring to Figure 4 and Figure 6 , the cavity of the separation cylinder 2 is provided with an annular separation groove 13, the separation groove 13 is sleeved on the output end of the feeding pipe 4 and is in a horizontal state, which is used for conveying the drilling fluid to the separation groove 13 through the feeding pipe 4, the outer wall surface of the separation groove 13 and the inner wall surface of the separation cylinder 2 are fixedly connected with a fixed rod 15, and a plurality of circular holes 20 are arranged at the groove bottom of the separation groove 13.

[0061] Through the horizontal sleeving structure of the annular separation groove 13, the drilling fluid forms an annular flow path after entering the separation groove 13 from the output end of the feeding pipe 4, which prolongs the residence time of the drilling fluid in the separation cylinder 2, and provides sufficient phase change space for the gasification of light hydrocarbon; the fixed rod 15 connected between the outer wall of the separation groove 13 and the inner wall of the cylinder body ensures the mechanical stability of the separation groove 13; the design of the equidistant circular holes 20 at the groove bottom makes the drilling fluid uniformly penetrate into the space below the separation groove 13, forming a multi-stage dispersion effect, preventing temperature gradient from being uneven due to local accumulation, and ensuring that the light hydrocarbon continuously gasifies under constant pressure environment. The horizontal annular separation groove 13 and the distributed pressure sensor arranged in a vertical distribution form a spatial cooperation, so that the pressure monitoring data more truly reflects the overall gasification environment in the separation cylinder 2.

[0062] Preferably, referring to Figure 7 , the device further comprises a driving motor 5, a circular plate 18 and a rotating part 14, the rotating part 14 comprises a rotating shaft 23, a separation plate 22, a separation block 21 and a plurality of supporting arms 19.

[0063] The circular plate 18 is arranged at the bottom of the top cover 10, the driving motor 5 is arranged at the upper end surface of the top cover 10, the output end of the driving motor 5 penetrates through the top cover 10 and is transmissionally connected with the circular plate 18, one end of each supporting arm 19 is fixedly connected with the bottom of the circular plate 18, the other end of each supporting arm 19 is fixedly connected with the separation block 21, the lower part of the separation block 21 is provided with a horizontal penetrating rotating shaft 23, and the two ends of the rotating shaft 23 are provided with the separation plate 22, which is used for accelerating the gas release of the drilling fluid in the separation groove 13.

[0064] Preferably, referring to Figure 7 , the cross section of the separation block 21 is Y-shaped; and the cross section of the separation plate 22 is triangular.

[0065] The driving motor 5 is fixedly installed at the top end of the top cover 10, and drives the circular plate 18 to rotate in working, and one end of the supporting arm 19 is fixedly installed at the bottom end of the circular plate 18, so that the circular plate 18 drives the supporting arm 19 to rotate synchronously, and the other end of the supporting arm 19 is fixedly connected with the separation block 21, the separation block 21 collides with the drilling fluid, and the release of the air in the drilling fluid is promoted, the separation block 21 is Y-shaped, and the separation block 21 rotates in the cavity of the separation groove 13, the separation plate 22 is fixedly installed at both ends of the rotating shaft 23, the separation plate 22 is triangular, and the separation plate 22 also rotates in the rotating process of the supporting arm 19, and the centrifugal force generated by the rotation helps to push the gas in the drilling fluid to the edge more quickly, so that the release process of the gas is accelerated.

[0066] Based on the same inventive concept, the application also provides a method for separating light hydrocarbon while drilling, which adopts the light hydrocarbon separation device as described above, and comprises the following steps:

[0067] S1, obtaining real-time temperature T of drilling fluid, real-time flow rate Q of drilling fluid and real-time pressure in the separation cylinder 2

[0068] S2, based on the obtained real-time temperature T of drilling fluid and real-time flow rate Q of drilling fluid, the target pressure of the separation cylinder 2 is calculated, and the target pressure of the separation cylinder 2 is calculated, and the target pressure of the separation cylinder 2 is calculated.

[0069]

[0070] Wherein, A is a temperature coefficient; B is a flow coefficient; C is a basic pressure constant;

[0071] S3, based on the target pressure of the separation cylinder 2 and the real-time pressure in the separation cylinder 2 , the pressure deviation is calculated, whether the pressure deviation is less than or equal to the preset threshold value is judged, if the judgment result is yes, the current state is maintained, if the judgment structure is no, the pressure in the separation cylinder 2 is adjusted through the air extraction pressure regulating assembly, and the step S1 is returned.

[0072] ​​By establishing a dynamic control model of temperature-flow-pressure, the phase stability control of light hydrocarbon is realized. First, the drilling fluid temperature and flow data are obtained in real time. Based on the temperature coefficient A, the positive compensation effect of temperature on the critical gasification pressure is reflected. The flow coefficient B reflects the physical characteristics that the increase of flow rate requires the reverse adjustment of the pressure in the separation cylinder 2. The basic pressure constant C guarantees the basic operating conditions of the system. By limiting the target pressure to be less than the critical gasification pressure corresponding to the real-time temperature, it is ensured that the light hydrocarbon is always above the gas phase equilibrium point. The pressure deviation calculation uses the difference between the real-time pressure and the target pressure for monitoring. When the deviation exceeds the preset threshold, the closed-loop regulation is triggered. Through the air extraction pressure regulating assembly, the pressure fluctuation is quickly responded, and the pressure in the separation cylinder 2 is maintained stable in the best interval required for light hydrocarbon gasification, effectively overcoming the problem of light hydrocarbon re-liquefaction caused by the decrease of ambient temperature in the traditional degassing device, and providing a continuous and stable gaseous light hydrocarbon sample for FID.

[0073] Preferably, step S2 can be replaced by the following steps:

[0074] The critical gasification pressure of light hydrocarbon corresponding to the current drilling fluid real-time temperature T is calculated by the virtual critical pressure formula The target pressure of the separation cylinder 2 is calculated based on the obtained drilling fluid real-time temperature T and drilling fluid real-time flow Q, which is Specifically,

[0075]

[0076] Wherein, A is the temperature coefficient; B is the flow coefficient; C is the basic pressure constant;

[0077] Determine whether is less than or equal to If the result is no, modify and return to step S1; if the result is yes, execute step S3;

[0078] The modification is specifically: reducing the temperature of the pipeline heater or enhancing the air extraction intensity of the air extraction pressure regulating assembly. The purpose of reducing the temperature of the pipeline heater is to reduce by reducing the real-time temperature T of the drilling fluid; the purpose of enhancing the air extraction intensity of the air extraction pressure regulating assembly is to reduce the real-time pressure in the separation cylinder 2 by adjusting the negative pressure of the air extraction pressure regulating assembly.

[0079] The virtual critical pressure formula is specifically:

[0080]

[0081] Wherein, is the molecular fraction of light hydrocarbon component i, and i is 1-8; Pc is the critical gasification pressure of light hydrocarbon corresponding to component i at the current drilling fluid real-time temperature T, and the unit is kPa.

[0082] In a specific embodiment of the present application, the pressure deviation is specifically: the real-time pressure in the separation cylinder 2 minus the target pressure of the separation cylinder 2 ; and the preset threshold is specifically: ±0.5 kPa.

[0083] By defining the pressure deviation as the difference between the real-time pressure and the target pressure, and limiting the preset threshold to ±0.5 kPa, the core feedback mechanism of the closed-loop control system is constructed, which directly reflects the deviation degree of the actual working condition from the ideal pressure state. The threshold of ±0.5 kPa is set based on the critical sensitivity of the phase change of light hydrocarbon, which not only avoids the increase of energy consumption caused by excessive adjustment, but also ensures that the pressure fluctuation does not break through the critical condition of light hydrocarbon liquefaction. When the difference between the real-time pressure and the target pressure exceeds the threshold, the air extraction pressure regulating assembly is triggered to perform dynamic compensation, and the pressure in the separation cylinder 2 is maintained stable in the critical pressure range required for light hydrocarbon gasification through high-precision pressure closed-loop control, thereby ensuring that the light hydrocarbon continuously exists in gaseous form. By quantifying the pressure deviation range and setting a precise threshold, accurate triggering and rapid response of pressure regulation are achieved, and the problem of repeated changes of light hydrocarbon phase caused by pressure control lag or insufficient precision in traditional methods is solved.

[0084] In a specific embodiment of the present application, a drilling light hydrocarbon separation device includes a support frame 1 fixedly installed on the ground, a top plate 6 fixedly installed at the top end of the support frame 1, and a separation cylinder 2 fixedly installed at the bottom end of the top plate 6. The separation cylinder 2 is located in the cavity of the support frame 1, and an air extraction pressure regulating assembly is arranged above the separation cylinder 2. The air extraction pressure regulating assembly includes a vacuum pump 8 and an electronic vacuum regulating valve 9. The output end of the vacuum pump 8 is connected to the input end of the electronic vacuum regulating valve 9 through an air pipe 12, and the output end of the electronic vacuum regulating valve 9 communicates with the inner cavity of the separation cylinder 2 through a top cover 10, and is used for extracting air in the cavity of the separation cylinder 2. Specifically, the vacuum pump 8 is fixedly installed at the top end of the top plate 6, the top end of the separation cylinder 2 is movably clamped with the top cover 10, the electronic vacuum regulating valve 9 is fixedly installed at the top end of the top cover 10, the electronic vacuum regulating valve 9 penetrates through the top cover 10, and the electronic vacuum regulating valve 9 and the vacuum pump 8 are connected through the air pipe 12. When the vacuum pump 8 works, the air in the cavity of the separation cylinder 2 is extracted through the air pipe 12, and the pressure in the cavity of the separation cylinder 2 is controlled.

[0085] The while-drilling light hydrocarbon separation device further comprises a pipeline heater 3, a feeding hose 24, a constant flow pump 7 and a feeding pipe 4, the constant flow pump 7 is arranged at a middle position of the feeding hose 24 and is used for controlling constant flow of the drilling fluid, the feeding hose 24 is in communication with one end of the feeding pipe 4; the pipeline heater 3 is sleeved on an outer wall surface of the feeding hose 24 and is used for constant temperature heating of the drilling fluid in the feeding hose 24; the feeding pipe 4 is fixedly penetrated through the separation cylinder 2, one end of the feeding pipe 4 is located in a cavity of the separation cylinder 2, and the drilling fluid enters the cavity of the separation cylinder 2 in sequence through the feeding hose 24 and the feeding pipe 4;

[0086] The bottom end of the separation cylinder 2 is provided with a discharge port 11, and the drilling fluid in the cavity of the separation cylinder 2 is discharged from the discharge port 11 after removing air; the feeding pipe 4 is S-shaped, a plurality of groups of support columns 17 are fixedly connected to one end of the feeding pipe 4 in the cavity of the separation cylinder 2, the plurality of groups of support columns 17 are arranged in a ring shape, and the plurality of groups of support columns 17 are commonly connected to the top hat 16 away from one end of the feeding pipe 4; the separation cylinder 2 is provided with a separation unit for promoting release of gas in the drilling fluid, the separation unit comprises a driving motor 5, a circular plate 18 and a rotating part 14, the rotating part 14 comprises a support arm 19, a rotating shaft 23, a separation plate 22 and a separation block 21; the cavity of the separation cylinder 2 is further provided with a separation groove 13, the separation groove 13 is sleeved on an outer wall surface of the feeding pipe 4, the separation groove 13 is in a horizontal state, a fixed rod 15 is fixedly connected between an outer wall surface of the separation groove 13 and an inner wall surface of the separation cylinder 2, a plurality of circular holes 20 are arranged at equal intervals at a bottom end of a cavity of the separation groove 13, and the drilling fluid flows out through the circular holes 20 and falls into the bottom end of the cavity of the separation cylinder 2; the driving motor 5 is fixedly installed at the top end of the top cover 10, an output shaft of the driving motor 5 is movably penetrated through the top cover 10 and is fixedly connected to the circular plate 18, and one end of the support arm 19 is fixedly installed at the bottom end of the circular plate 18; the other end of the support arm 19 is fixedly connected to the separation block 21, the separation block 21 is Y-shaped, the rotating shaft 23 movably penetrates through the separation block 21 through a sealing bearing, and the separation plate 22 is fixedly installed at two ends of the rotating shaft 23, and the separation plate 22 is triangular.

[0087] The while-drilling light hydrocarbon separation device further comprises a pipeline heater 3, a feeding hose 24, a constant flow pump 7 and a feeding pipe 4, the constant flow pump 7 is arranged at a middle position of the feeding hose 24 and is used for controlling constant flow of the drilling fluid, the feeding hose 24 is in communication with one end of the feeding pipe 4; the pipeline heater 3 is sleeved on an outer wall surface of the feeding hose 24 and is used for constant temperature heating of the drilling fluid in the feeding hose 24; the feeding pipe 4 is fixedly penetrated through the separation cylinder 2, one end of the feeding pipe 4 is located in a cavity of the separation cylinder 2, and the drilling fluid enters the cavity of the separation cylinder 2 in sequence through the feeding hose 24, the feeding pipe 4;

[0088] The pipeline heater 3, the constant flow pump 7, the vacuum pump 8 and the electronic vacuum regulating valve 9 can adopt models that can meet the working requirements. In a specific embodiment of the present application, the pipeline heater 3 adopts a pipeline heater with a model of SRY2-220 / 3, the constant flow pump 7 adopts a BT100-1F micro peristaltic pump, the vacuum pump 8 adopts a 2XZ-4 rotary vane vacuum pump, and the electronic vacuum regulating valve 9 adopts a vacuum regulating valve with a model of ZDLP-16C.

[0089] In a specific embodiment of the present application, the method of the drilling light hydrocarbon separation device includes the following steps: the pipeline heater 3 and the vacuum pump 8 are turned on in advance, and then the constant flow pump 7 is started to make the drilling fluid enter the cavity of the separation cylinder 2 through the feeding hose 24 and the feeding pipe 4; after the drilling fluid enters the cavity of the separation cylinder 2, the driving motor 5 is started to drive the circular plate 18 and the supporting arm 19 to rotate, and the drilling fluid flows out from one end of the feeding pipe 4 in the cavity of the separation cylinder 2 and falls into the cavity of the separation groove 13; the supporting arm 19 contacts the drilling fluid in the cavity of the separation groove 13 during the rotation, and the separation plate 22 also rotates during the rotation of the supporting arm 19 to accelerate the release of the gas in the drilling fluid; the electronic vacuum regulating valve 9 at the top end of the top cover 10 is used to control the amount of gas discharged from the cavity of the gas pipe 12 to complete the pressure control in the cavity of the separation cylinder 2.

[0090] The pressure control principle is as follows: based on the dynamic correlation between the pressure in the separation cylinder 2 and the gaseous stability of light hydrocarbon, the real-time temperature T of the drilling fluid, the real-time flow rate Q of the drilling fluid and the real-time pressure P in the separation cylinder 2 are collected in real time , the optimal opening of the electronic vacuum regulating valve 9 is output by using an algorithm to realize the accurate control of the pressure in the separation cylinder 2 and ensure that the light hydrocarbon is always in a stable gaseous state.

[0091] The opening K (%) of the electronic vacuum regulating valve 9 is used to control the amount of gas pumped by the vacuum pump 8, and the range of the opening is 0-100%, which corresponds to the full closing to the full opening of the electronic vacuum regulating valve 9, and the specific steps include the following steps:

[0092] The target pressure calculation formula of the separation cylinder 2 is obtained by fitting the experimental data:

[0093]

[0094] Wherein, 0.9 is the temperature coefficient (kPa / ℃), 0.4 is the flow coefficient (kPa min / L), and 55 is the basic pressure constant (kPa);

[0095] The real-time temperature T of the drilling fluid, the real-time flow rate Q of the drilling fluid and the real-time pressure P in the separation cylinder 2 are collected in real time , the real-time temperature T of the drilling fluid and the real-time flow rate Q of the drilling fluid are brought into the target pressure calculation formula to obtain the target pressure P of the separation cylinder 2 ;

[0096] target pressure of the separation cylinder 2 and the real-time pressure in the separation cylinder 2 , the pressure deviation is calculated;

[0097] The opening adjustment amount of the electronic vacuum regulating valve 9 is calculated by using a simple proportional algorithm:

[0098]

[0099] wherein 6 is a proportional coefficient (% / kPa); is the opening adjustment amount;

[0100] The final opening of the electronic vacuum regulating valve 9 is:

[0101]

[0102] wherein, is the initial opening of the electronic vacuum regulating valve 9, is the final opening and 0≤K≤100%.

[0103] The electronic vacuum regulating valve 9 is controlled to adjust according to the final opening After adjustment, the real-time pressure in the separation cylinder 2 is collected again until the pressure deviation meets the preset threshold.

[0104] In a specific embodiment of the present application, The value of K is 30%-50%.

[0105] The method of the present application can quickly respond to fluctuations in drilling fluid flow and temperature, ensuring that light hydrocarbons are always in a stable gaseous interval; the temperature coefficient and the flow coefficient can be adjusted according to the characteristics of different light hydrocarbon components, and the adaptability is strong, which meets the pressure control requirements of the while-drilling light hydrocarbon separation device.

[0106] The target pressure calculation formula is obtained by fitting a plurality of orthogonal experimental data, specifically:

[0107] The experimental selects a typical drilling fluid sample on site, wherein the light hydrocarbon component is C1-C8, the molecular fraction refers to the block geological data, under the operating conditions of a temperature range of 50-150 DEG C and a flow range of 10-50 L / min, 12 groups of variable combinations are set, the temperature gradient in the variable combination is 20 DEG C, the flow gradient in the variable combination is 10 L / min, and each experiment is repeated 3 times;

[0108] The separation cylinder pressure data when the light hydrocarbon separation efficiency is greater than or equal to 90% under each working condition are collected, the least square method is used to linearly regress and fit the relationship between the real-time temperature T of the drilling fluid, the real-time flow Q of the drilling fluid and the optimal pressure, and finally the target pressure calculation formula is obtained: , goodness of fit ≥0.92. The constraint condition of the formula is: when T∈[50, 150]℃, Q∈[10, 50]L / min, the calculated is always lower than 95% of the corresponding working condition , through sample group critical pressure calculation, 5% safety margin is reserved to ensure that the gasification requirements of ≤ are met.

[0109] Finally, it should be noted that the above examples are only one or more specific forms of the present invention, and their purpose is to clearly explain the concept, principle and application of the present invention through specific examples, and not to limit the scope of protection of the present invention to these specific examples. In fact, the true value of the present invention lies in its technical ideas and innovations, not its forms or means of implementation.

[0110] For those skilled in the art, after thoroughly reading and understanding the technical solutions of the present invention, they have the ability to make various forms of changes, modifications or equivalent replacements to the specific embodiments of the invention based on their own professional knowledge and skills. These changes may include but are not limited to adjusting the value range of technical parameters, optimizing the algorithm process to improve efficiency, replacing part of the technical components to achieve better compatibility or reduce costs, etc. As long as the technical solutions after these changes still maintain the technical features required by the original invention, i.e. still can realize the core functions and effects of the present invention, these changes should be considered as falling within the scope of protection of the claims of the present invention.

[0111] In addition, with the continuous progress and development of technology, new technical means and methods are constantly emerging, which also provides a broad space for further improvement and perfection of the present invention. Therefore, the scope of protection of the present invention should also include those reasonable and foreseeable improvements and extensions based on the existing technology, as long as these improvements and extensions do not deviate from the basic principles and core ideas of the present invention, they should be considered as equivalents of the present invention, and also be protected by the patent right.

Claims

1. A light hydrocarbon separation device for drilling, characterized in that, The system includes a separator (2), a vacuum pressure regulating assembly, a feed hose (24), a feed pipe (4), a pipeline heater (3), and a controller. A top cover (10) is provided on the top of the separator (2). The outlet of the vacuum pressure regulating assembly passes through the top cover (10) and communicates with the inner cavity of the separator (2). A constant flow pump (7) is installed on the feed hose (24) to control the flow rate of the drilling fluid. The output end of the feed hose (24) is connected to the input end of the feed pipe (4), and the output end of the feed pipe (4) passes through the side wall of the separator (2) and connects to the separator. (2) is connected to the inner cavity of the separator (2) for conveying drilling fluid to the inner cavity of the separator (2); the pipe heater (3) is sleeved on the outer wall of the feed hose (24) for heating the drilling fluid in the feed hose (24) at a constant temperature; a temperature sensor is installed on the pipe heater (3) for obtaining the real-time temperature T of the drilling fluid; a flow sensor is installed on the constant flow pump (7) for obtaining the real-time flow rate Q of the drilling fluid delivered to the separator (2) per unit time; a pressure sensor is installed inside the separator (2) for obtaining the real-time pressure inside the separator (2). The temperature sensor, flow sensor, and pressure sensor are electrically connected to the controller, which is electrically connected to the air extraction and pressure regulating assembly. This assembly is used to adjust the real-time drilling fluid temperature T, real-time drilling fluid flow rate Q, and real-time pressure inside the separator (2) based on the obtained data. Adjust the air extraction and pressure regulating components to make the pressure inside the separation cylinder lower than the critical vaporization pressure of light hydrocarbons corresponding to the current real-time temperature T of the drilling fluid. The vacuum pump pressure regulating assembly includes a vacuum pump (8) and an electronic vacuum regulating valve (9). The output end of the vacuum pump (8) is connected to the input end of the electronic vacuum regulating valve (9) via a gas pipe (12). The output end of the electronic vacuum regulating valve (9) serves as the outlet of the vacuum pump pressure regulating assembly. The pressure sensor consists of several distributed pressure sensors, which are vertically arranged at equal intervals inside the separation cylinder (2); the real-time pressure inside the separation cylinder (2) It equals the average value of all distributed pressure sensors.

2. The drilling light hydrocarbon separation device according to claim 1, characterized in that, It also includes a support frame (1) fixedly installed on the ground, with a top plate (6) fixedly installed at the top of the support frame (1), and the separation cylinder (2) located inside the cavity of the support frame (1) and fixed at the bottom of the top plate (6).

3. The drilling light hydrocarbon separation device according to claim 1, characterized in that, It also includes a top cap (16) and several support columns (17); the feed pipe (4) is in the shape of a flat S, and several support columns (17) are fixed in a ring array on the output end of the feed pipe (4); the top cap (16) is fixedly connected to the end of several support columns (17) away from the feed pipe (4).

4. The drilling light hydrocarbon separation device according to claim 3, characterized in that, The cavity of the separator (2) is provided with an annular separator (13). The separator (13) is sleeved on the output end of the feed pipe (4) and the separator (13) is in a horizontal state. It is used to transport drilling fluid to the separator (13) through the feed pipe (4). A fixing rod (15) is fixedly connected between the outer wall of the separator (13) and the inner wall of the separator (2). The bottom of the separator (13) is provided with several equally spaced circular holes (20).

5. A drilling-while-drilling light hydrocarbon separation device according to claim 4, characterized in that, It also includes a drive motor (5), a circular plate (18) and a rotating part (14), the rotating part (14) including a rotating shaft (23), a separating plate (22), a separating block (21) and several support arms (19); The circular plate (18) is set at the bottom of the top cover (10), and the drive motor (5) is set on the upper surface of the top cover (10). The output end of the drive motor (5) passes through the top cover (10) and is connected to the circular plate (18). One end of several support arms (19) is fixedly connected to the bottom of the circular plate (18) at intervals. The other end of each support arm (19) is fixedly connected to the separation block (21). A horizontally penetrating rotating shaft (23) is set at the lower part of the separation block (21). Separation plates (22) are set at both ends of the rotating shaft (23). The separation plates (22) are used to accelerate the gas release of drilling fluid in the separation tank (13).

6. A drilling-while-drilling light hydrocarbon separation device according to claim 5, characterized in that, The cross-section of the separating block (21) is Y-shaped; the cross-section of the separating plate (22) is triangular.

7. A method for separating light hydrocarbons while drilling, characterized in that, The drilling light hydrocarbon separation device as described in any one of claims 1 to 6 includes the following steps: S1. Obtain the real-time drilling fluid temperature T, real-time drilling fluid flow rate Q, and real-time pressure inside the separator (2). ; S2. Based on the obtained real-time drilling fluid temperature T and real-time drilling fluid flow rate Q, the target pressure of the separator (2) is calculated. Specifically: Where 0.9 is the temperature coefficient (kPa / ℃) and 0.4 is the flow coefficient (kPa). The basic pressure constant is 55 (kPa). The constraints of this formula are: T∈[50,150]℃, Q∈[10,50]L / min; S3, Target pressure based on separator (2) Real-time pressure inside the separator (2) Calculate the pressure deviation and determine whether the pressure deviation is less than or equal to the preset threshold. If the determination result is yes, maintain the current state; if the determination result is no, adjust the pressure in the separator (2) through the air extraction and pressure regulating component and return to step S1.

8. The method for separating light hydrocarbons while drilling according to claim 7, characterized in that, Step S2 can be replaced by the following steps: The critical vaporization pressure of light hydrocarbons at the current real-time drilling fluid temperature T is calculated using the virtual critical pressure formula. ; The specific formula for the virtual critical pressure is as follows: in, Let i be the molecular fraction of light hydrocarbon component i, where i ranges from 1 to 8. The critical vaporization pressure of light hydrocarbons corresponding to component i at the current drilling fluid real-time temperature T is expressed in kPa. Based on the obtained real-time drilling fluid temperature T and real-time drilling fluid flow rate Q, the target pressure of the separator (2) is calculated. Specifically: Where 0.9 is the temperature coefficient (kPa / ℃) and 0.4 is the flow coefficient (kPa). The basic pressure constant is 55 (kPa). The constraints of this formula are: T∈[50,150]℃, Q∈[10,50]L / min; judge Is it less than or equal to? If the judgment result is negative, then make corrections and return to step S1; if the judgment result is positive, then execute step S3. The specific modifications are: reducing the temperature of the pipeline heater or increasing the suction power of the suction pressure regulating component.

Images