Method and device for monitoring formation pressure while drilling

Abstract

The invention discloses a while-drilling pressure formation force monitoring method and a while-drilling pressure formation force monitoring device. The method comprises the steps that logging-while-drilling parameters of at least one normal-pressure well section in drilled sections of a well to be monitored are obtained, and the first drilling fluid outlet temperature slope of the normal-pressure well section is determined according to the logging-while-drilling parameters of the normal-pressure well section; acquiring logging-while-drilling parameters of the current drilling well section of the to-be-monitored well, and determining a second drilling fluid outlet temperature slope of the current drilling well section according to the logging-while-drilling parameters of the current drilling well section; according to the first drilling fluid outlet temperature slope and the second drilling fluid outlet temperature slope, the formation pressure coefficient change condition is determined; and determining whether the formation pressure is normal or not according to the formation pressure coefficient change condition and a preset formation pressure coefficient change condition threshold value. According to the pressure transition zone logging parameter response characteristics, the formation pressure change can be found in the actual drilling process, and therefore the abnormal pressure early warning effect is achieved.

Description

Technical Field

[0001] The invention relates to the field of oil and gas drilling, and in particular to a method and device for monitoring formation pressure while drilling. Background Art

[0002] With the continuous growth of energy demand and the increasing depletion of shallow oil and gas resources on land, the focus of oil and gas exploration and development has shifted from shallow layers to deep and ultra-deep layers. During the drilling process, when the formation is subjected to the drilling action of the drill bit, the liquid in the formation rock flows out and generates formation pressure. Under the influence of factors such as undercompaction, continuous changes in underground structures, the enhancement of water pressure due to high temperature in the formation, hydrocarbon generation in sediments, and lateral pressure of water levels, the formation pressure will become abnormal. Formation pressure is divided into three states: abnormally high pressure, normal pressure, and abnormally low pressure. In the field of oil and gas drilling, the existence of abnormally high pressure often leads to complex accidents such as oil and gas water intrusion, overflow, well gust, and even blowout. Therefore, the early prediction of abnormally high pressure is particularly important. In order to predict abnormally high pressure, a variety of pressure calculation models for predicting formations based on seismic or adjacent well data have been proposed in the prior art. Summary of the invention

[0003] The inventors of this application have found that, due to the limitations of seismic data accuracy or the weak reference of adjacent well data, the accuracy of predicting formation pressure in the prior art is generally not high, and it is difficult to play an early warning role in the drilling process. The increase in formation pressure is not instantaneous, but there is a process of lifting. This gradual lifting process is called the pressure transition zone. At present, there is a lack of methods to predict the change of formation pressure in the drilling process based on the response characteristics of logging parameters in the pressure transition zone.

[0004] In view of the above problems, the present invention is proposed to provide a method and device for monitoring formation pressure while drilling that overcomes the above problems or at least partially solves the above problems. The method identifies the pressure transition zone by changing the formation pressure coefficient, thereby predicting the existence of abnormally high pressure in advance, thereby achieving the purpose of early warning.

[0005] In a first aspect, an embodiment of the present invention provides a method for monitoring formation pressure while drilling, comprising:

[0006] Obtaining logging while drilling parameters of at least one normal pressure well section in the drilled well section of the well to be monitored, and determining a first drilling fluid outlet temperature slope of the normal pressure well section according to the logging while drilling parameters of the normal pressure well section;

[0007] Obtaining logging while drilling parameters of the current drilling section of the well to be monitored, and determining the second drilling fluid outlet temperature slope of the current drilling section according to the logging while drilling parameters of the current drilling section;

[0008] Determining a change in formation pressure coefficient according to a first drilling fluid outlet temperature slope and a second drilling fluid outlet temperature slope;

[0009] Whether the formation pressure is normal is determined based on the change in the formation pressure coefficient and a preset threshold for the change in the formation pressure coefficient.

[0010] In some optional embodiments, obtaining the logging while drilling parameters of at least one normal pressure well section in the drilled section of the well to be monitored, and determining the first drilling fluid outlet temperature slope of the normal pressure well section according to the logging while drilling parameters of the normal pressure well section, comprises:

[0011] Obtaining drilling fluid temperature data and corresponding well depth data in the logging while drilling parameters of a normal pressure well section in the drilled section of the well to be monitored; determining the first drilling fluid outlet temperature slope of the normal pressure well section according to the obtained drilling fluid temperature data and corresponding well depth data in the logging while drilling parameters of the normal pressure well section; or

[0012] The drilling fluid temperature data and corresponding well depth data in the logging while drilling parameters of at least two normal pressure well sections in the drilled section of the well to be monitored are obtained; the first drilling fluid outlet temperature slope of each normal pressure well section is determined according to the drilling fluid temperature data and the corresponding well depth data in the logging while drilling parameters of each normal pressure well section; the first drilling fluid outlet temperature slope of each normal well section is weighted averaged to obtain the first drilling fluid outlet temperature slope of the normal pressure well section.

[0013] In some optional embodiments, determining the first drilling fluid outlet temperature slope of each normal pressure well section according to the drilling fluid temperature data and the corresponding well depth data in the logging while drilling parameters of each normal pressure well section includes:

[0014] The first drilling fluid outlet temperature slope in the normal pressure well section is determined using the following formula:

[0015] Among them, k t1 is the first drilling fluid outlet temperature slope, t max1 and t min1 are the maximum and minimum drilling fluid outlet temperatures of the drilled normal pressure well section, respectively. t max1 The corresponding well depth, t min1 The corresponding well depth, where Greater than

[0016] In some optional embodiments, obtaining the logging while drilling parameters of the current drilling section of the well to be monitored, and determining the second drilling fluid outlet temperature slope of the current drilling section according to the logging while drilling parameters of the current drilling section, includes:

[0017] Obtain the drilling fluid outlet temperature and the corresponding well depth of the well section currently being drilled, and determine the second drilling fluid outlet temperature slope according to the following formula: Among them, k t2 is the second drilling fluid outlet temperature slope, t max2 and t min2 are the maximum and minimum drilling fluid outlet temperatures of the well section being drilled, respectively. t max2 The corresponding well depth, t min2 The corresponding well depth, where Greater than

[0018] In some optional embodiments, determining the change of the formation pressure coefficient according to the first drilling fluid outlet temperature slope and the second drilling fluid outlet temperature slope includes:

[0019] The formation pressure variation coefficient is determined by the following formula: Where Δt is the formation pressure variation coefficient;

[0020] According to the value of the formation pressure coefficient, the change of the formation pressure coefficient is determined.

[0021] In some optional embodiments, determining whether the formation pressure is normal according to the change of the formation pressure coefficient and a preset threshold of the change of the formation pressure coefficient includes:

[0022] If the formation pressure coefficient is less than a preset formation pressure coefficient change threshold, it is determined that the formation pressure is normal;

[0023] If the formation pressure coefficient is not less than a preset formation pressure coefficient change threshold, the formation pressure is determined to be abnormal.

[0024] In some optional embodiments, after determining that the formation pressure is abnormal based on the formation pressure coefficient change and a preset formation pressure coefficient change threshold, the user is immediately prompted to stop drilling and / or adjust the drilling fluid parameters.

[0025] In some optional embodiments, the above method further includes:

[0026] Periodically obtain changes in formation pressure coefficient at preset time intervals;

[0027] If the formation pressure is determined to be normal based on the change in the formation pressure coefficient, the drilling work is performed normally; if the formation pressure is determined to be abnormal based on the change in the formation pressure coefficient, an abnormal pressure warning message is sent.

[0028] In a second aspect, an embodiment of the present invention provides a formation pressure monitoring device while drilling, comprising:

[0029] The data acquisition module is used to obtain the logging parameters of at least one normal pressure section in the drilled section of the well to be monitored; and obtain the logging parameters of the current drilling section of the well to be monitored;

[0030] The data processing module is used to determine the first drilling fluid outlet temperature slope of the normal pressure well section according to the logging parameters of the normal pressure well section; determine the second drilling fluid outlet temperature slope of the current drilling well section according to the logging parameters of the current drilling well section;

[0031] The pressure monitoring module determines the change of the formation pressure coefficient according to the first drilling fluid outlet temperature slope and the second drilling fluid outlet temperature slope; and determines whether the formation pressure is normal according to the change of the formation pressure coefficient and a preset threshold of the change of the formation pressure coefficient.

[0032] An embodiment of the present invention provides a computer storage medium, in which computer executable instructions are stored. When the computer executable instructions are executed by a processor, a method for monitoring formation pressure while drilling is implemented.

[0033] An embodiment of the present invention provides a computer device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements a method for monitoring formation pressure while drilling when executing the program.

[0034] The beneficial effects of the above technical solution provided by the embodiment of the present invention include at least:

[0035] The method obtains the logging while drilling parameters of at least one normal pressure section in the drilled section of the well to be monitored, and determines the first drilling fluid outlet temperature slope of the normal pressure section according to the logging while drilling parameters of the normal pressure section; obtains the logging while drilling parameters of the current drilling section of the well to be monitored, and determines the second drilling fluid outlet temperature slope of the current drilling section according to the logging while drilling parameters of the current drilling section; determines the change of the formation pressure coefficient according to the first drilling fluid outlet temperature slope and the second drilling fluid outlet temperature slope; and then determines whether the formation pressure is normal according to the change of the formation pressure coefficient and a preset threshold value of the change of the formation pressure coefficient. Compared with the traditional method of predicting formation pressure based on the accuracy of seismic data or data from adjacent wells, the method for monitoring formation pressure while drilling of the present invention predicts formation pressure by acquiring logging parameters while drilling. When predicting formation pressure, the drilling fluid outlet temperature slopes of the normal pressure well section and the well section being drilled are analyzed based on the logging parameters while drilling, and the formation pressure changes are analyzed based on the slopes of the two, so that the formation pressure prediction is more accurate and the changes in formation pressure can be monitored in real time, especially the formation pressure changes in the well section being drilled. Through quantitative analysis of the outlet temperature slope and the formation pressure changes, the existence of abnormally high pressure can be predicted in advance, thereby achieving the purpose of early warning.

[0036] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description, claims, and drawings.

[0037] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0039] Figure 1 Flow chart of a method for monitoring formation pressure while drilling in an embodiment of the present invention;

[0040] Figure 2 A schematic diagram of logging while drilling parameter characteristics and formation pressure in an embodiment of the present invention;

[0041] Figure 3 Schematic diagram of the structure of the formation pressure monitoring device while drilling in an embodiment of the present invention. DETAILED DESCRIPTION

[0042] In the field of oil and gas drilling, the existence of abnormally high pressure often leads to complex accidents such as oil and gas water intrusion, overflow, well kick and even blowout, so the early prediction of abnormally high pressure is particularly important. In order to predict abnormally high pressure, a variety of pressure calculation models for predicting formations based on seismic or adjacent well data have been proposed in the prior art. However, the existing technology is limited by the accuracy of seismic data or the weak reference of adjacent wells, and the prediction accuracy is generally not high, which makes it difficult to play an early warning role, especially for the pressure transition zone, there is a lack of corresponding pressure prediction methods.

[0043] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0044] The inventors of this application have found that changes in drilling fluid properties are more sensitive to changes in abnormal pressure. By monitoring changes in parameters such as drilling fluid outlet temperature, flow rate, and density, the purpose of pressure monitoring while drilling can be achieved to a certain extent. When drilling into a pressure transition zone, the total hydrocarbon base value will rise. However, through a large amount of well data back-judgment analysis, it is found that when in the pressure transition zone, in addition to total hydrocarbons, the growth rate of the drilling fluid outlet temperature, that is, the slope, will increase due to drilling into the pressure transition zone. Therefore, changes in formation pressure can be monitored by monitoring changes in the drilling fluid outlet temperature. Based on this, in order to solve the problem of low prediction accuracy and difficulty in providing pressure warnings during drilling in the prior art, an embodiment of the present invention provides a method for monitoring formation pressure while drilling. According to the response characteristics of logging parameters in the pressure transition zone, changes in formation pressure are predicted in advance during the drilling process to achieve the purpose of providing pressure warnings in advance.

[0045] Example

[0046] The embodiment of the present invention provides a method for monitoring formation pressure while drilling, the process of which is as follows: Figure 1 As shown, the following steps are included:

[0047] Step S101: obtaining logging while drilling parameters of at least one normal pressure well section in the drilled section of the well to be monitored, and determining the first drilling fluid outlet temperature slope of the normal pressure well section according to the logging while drilling parameters of the normal pressure well section;

[0048] Step S102: acquiring the logging while drilling parameters of the current drilling section of the well to be monitored, and determining the second drilling fluid outlet temperature slope of the current drilling section according to the logging while drilling parameters of the current drilling section;

[0049] Step S103: determining a change in formation pressure coefficient according to the first drilling fluid outlet temperature slope and the second drilling fluid outlet temperature slope;

[0050] Step S104: Determine whether the formation pressure is normal based on the change in the formation pressure coefficient and a preset threshold value for the change in the formation pressure coefficient.

[0051] Preferably, in the above step S101, obtaining the logging while drilling parameters of at least one normal pressure well section in the drilled section of the well to be monitored, and determining the first drilling fluid outlet temperature slope of the normal pressure well section according to the logging while drilling parameters of the normal pressure well section, comprises:

[0052] Obtaining drilling fluid temperature data and corresponding well depth data in the logging while drilling parameters of a normal pressure well section in the drilled section of the well to be monitored; determining the first drilling fluid outlet temperature slope of the normal pressure well section according to the obtained drilling fluid temperature data and corresponding well depth data in the logging while drilling parameters of the normal pressure well section; or

[0053] The drilling fluid temperature data and corresponding well depth data in the logging while drilling parameters of at least two normal pressure well sections in the drilled section of the well to be monitored are obtained; the first drilling fluid outlet temperature slope of each normal pressure well section is determined according to the drilling fluid temperature data and the corresponding well depth data in the logging while drilling parameters of each normal pressure well section; the first drilling fluid outlet temperature slope of each normal well section is weighted averaged to obtain the first drilling fluid outlet temperature slope of the normal pressure well section.

[0054] Since there may be more than one normal pressure section in the drilled section, when determining the first drilling fluid outlet temperature slope of the normal pressure section, a normal pressure section in the drilled section can be selected, and the first drilling fluid outlet temperature slope of the normal pressure section can be determined according to its logging while drilling parameters; or two or more normal pressure sections can be selected, and a first drilling fluid outlet temperature slope can be determined based on the logging while drilling parameters of each section, and the two or more temperature slopes can be weighted averaged as the first drilling fluid outlet temperature slope of the normal pressure section, thereby further improving the accuracy of the obtained first drilling fluid outlet temperature slope.

[0055] During drilling, as the drilling depth becomes deeper and deeper, the formation pressure will gradually increase. The increase in formation pressure is not instantaneous, but there is a process of lifting. This gradual lifting process is called the pressure transition zone. By obtaining the logging parameters of the pressure transition zone, the changes in formation pressure can be more accurately perceived. After data analysis, it is found that the growth rate of the drilling fluid outlet temperature, that is, the slope, will increase due to the pressure transition zone encountered during drilling. Therefore, the changes in formation pressure can be monitored by monitoring the changes in the drilling fluid outlet temperature to achieve the role of early warning.

[0056] Preferably, determining the first drilling fluid outlet temperature slope of each normal pressure well section according to the drilling fluid temperature data and the corresponding well depth data in the logging while drilling parameters of each normal pressure well section includes:

[0057] The first drilling fluid outlet temperature slope in the normal pressure well section is determined using the following formula:

[0058] Where K t1 is the first drilling fluid outlet temperature slope, t max1 and t min1 are the maximum and minimum drilling fluid outlet temperatures of the drilled normal pressure well section, respectively. t max1 The corresponding well depth, t min1 The corresponding well depth, where Greater than

[0059] For example, this embodiment takes the HT101 well in actual exploration as an example, selects the normal pressure section 5400m-5560m of the well to be monitored, and selects the following logging parameters while drilling of the normal pressure section, t max =69.5,t min =66.3, H tmax =5539, By the formula: The calculated slope of the first drilling fluid outlet temperature is k t1 =0.0301.

[0060] Preferably, in the above step S102, the logging while drilling parameters of the current drilling section of the well to be monitored are obtained, and the second drilling fluid outlet temperature slope of the current drilling section is determined according to the logging while drilling parameters of the current drilling section, including:

[0061] Obtain the drilling fluid outlet temperature and the corresponding well depth of the well section currently being drilled, and determine the second drilling fluid outlet temperature slope according to the following formula: where k t2 is the second outlet temperature slope, t max2 and t min2 are the maximum and minimum drilling fluid outlet temperatures of the well section being drilled, respectively. t max2 The corresponding well depth, t min2 The corresponding well depth, where Greater than

[0062] For example, this embodiment takes the HT101 well in actual exploration as an example, obtains the current drilling section 5560-5660m of the well to be monitored, and selects the following logging parameters t of the current drilling section max =67.1,t min =66.9, By formula: The calculated slope of the second drilling fluid outlet temperature is k t2 =0.0024.

[0063] Preferably, in the above step S103, determining the change of the formation pressure coefficient according to the first drilling fluid outlet temperature slope and the second drilling fluid outlet temperature slope includes:

[0064] The formation pressure variation coefficient is determined by the following formula: Where Δt is the formation pressure variation coefficient;

[0065] According to the value of the formation pressure coefficient, the change of the formation pressure coefficient is determined.

[0066] For example, the calculated first drilling fluid outlet temperature slope and the calculated second drilling fluid outlet temperature slope are used to determine the formation pressure coefficient through the following formula: The final formation pressure coefficient is Δt = 0.0807. The outlet temperature of the drilling fluid is related to the formation pressure coefficient. The temperature change is sensitive and can be accurately measured. Therefore, the change of the formation pressure coefficient can be determined based on the change of the outlet temperature of the drilling fluid.

[0067] Preferably, in the above step S104, determining whether the formation pressure is normal according to the change of the formation pressure coefficient and a preset threshold of the change of the formation pressure coefficient includes:

[0068] If the formation pressure coefficient is less than a preset formation pressure coefficient change threshold, it is determined that the formation pressure is normal;

[0069] If the formation pressure coefficient is not less than a preset formation pressure coefficient change threshold, the formation pressure is determined to be abnormal.

[0070] For example, in this embodiment, when the preset formation pressure coefficient change threshold is finally determined to be 1.5 through the back-judgment analysis of a large amount of logging parameter information of the HT101 well, the predicted formation pressure change is closer to the actual situation. Of course, different wells have different preset formation pressure coefficient change thresholds due to their different logging parameters. In the actual exploration process, a suitable preset formation pressure coefficient change threshold can be determined according to the actual situation; the formation pressure coefficient of the well section 5560-5660m during the drilling process is Δt=0.0807, which is less than the preset formation pressure coefficient change threshold of 1.5. Therefore, it can be judged that there is no abnormal formation pressure in the well section and drilling can continue; when drilling the well section 5660-5733m, the following logging parameters t are obtained: max =67.8,t min =61.6, By formula The calculated outlet temperature of the second drilling fluid is k t2 =0.0590, according to the formula The calculated formation pressure coefficient is Δt = 1.96, where k t1 The value refers to the normal pressure section 5400-5560m. The formation pressure coefficient 1.96 at this time is greater than the preset formation pressure coefficient change threshold 1.5, indicating that the 5660-5790m section encountered abnormal pressure during drilling. Figure 2 This is a schematic diagram of the characteristics of logging parameters while drilling and formation pressure, see Figure 2 As shown, logging parameters are collected for the five-tuple formation of the HT101 well and changes in formation pressure are monitored. According to the parameter calculation in this embodiment, the normal pressure section selected is 5400-5560m. When drilling the 5560-5660m section, logging parameters are collected and the formation pressure coefficient is calculated to be 0.0807, which is judged to be normal pressure. The 5660-5733 section is continued to be drilled, and logging parameters are collected and the formation pressure coefficient is calculated to be 1.96, which is judged to have abnormal formation pressure in this section. Figure 2 The middle dot is the measured point of formation pressure. The measured points verified that there was abnormal formation pressure at 5710-5725m, and water intrusion occurred during the actual drilling process. The above judgment results are correct and can meet the on-site construction requirements.

[0071] Preferably, after determining that the formation pressure is abnormal based on the formation pressure coefficient change and the preset formation pressure coefficient change threshold, the user is immediately prompted to stop drilling and / or adjust the drilling fluid parameters.

[0072] When abnormal pressure is detected, the drilling team is notified immediately to respond, prompting the user to stop drilling and / or adjust drilling fluid parameters to avoid construction risks and improve the safety and efficiency of drilling work.

[0073] Preferably, the above-mentioned formation pressure monitoring method while drilling further includes:

[0074] Periodically obtain changes in formation pressure coefficient at preset time intervals;

[0075] If the formation pressure is determined to be normal based on the change in the formation pressure coefficient, the drilling work is performed normally; if the formation pressure is determined to be abnormal based on the change in the formation pressure coefficient, an abnormal pressure warning message is sent.

[0076] Based on the same inventive concept, the embodiment of the present invention also provides a formation pressure monitoring device while drilling, which can be arranged in a device having a computer instruction processing function. The structure of the device is as follows: Figure 3 As shown, including:

[0077] The data acquisition module 11 is used to obtain the logging parameters while drilling of at least one normal pressure section in the drilled section of the well to be monitored; and obtain the logging parameters while drilling of the current drilling section of the well to be monitored.

[0078] The data processing module 12 is used to determine the first drilling fluid outlet temperature slope of the normal pressure section according to the logging parameters of the normal pressure section; and determine the second drilling fluid outlet temperature slope of the current drilling section according to the logging parameters of the current drilling section.

[0079] The pressure monitoring module 13 determines the change of the formation pressure coefficient according to the first drilling fluid outlet temperature slope and the second drilling fluid outlet temperature slope; and determines whether the formation pressure is normal according to the change of the formation pressure coefficient and a preset formation pressure coefficient change threshold.

[0080] Preferably, the above-mentioned device further comprises an early warning prompt module 14, which is used to send abnormal pressure warning information when the formation pressure is determined to be abnormal based on the change of the formation pressure coefficient.

[0081] Regarding the formation pressure monitoring device while drilling in the above-mentioned embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated here.

[0082] The above method and device of the embodiment of the present invention obtains the logging while drilling parameters of at least one normal pressure well section in the drilled section of the well to be monitored, and determines the first drilling fluid outlet temperature slope of the normal pressure well section according to the logging while drilling parameters of the normal pressure well section; obtains the logging while drilling parameters of the current drilling well section of the well to be monitored, and determines the second drilling fluid outlet temperature slope of the current drilling well section according to the logging while drilling parameters of the current drilling well section; determines the change of the formation pressure coefficient according to the first drilling fluid outlet temperature slope and the second drilling fluid outlet temperature slope; and then determines whether the formation pressure is normal according to the change of the formation pressure coefficient and the preset threshold of the change of the formation pressure coefficient. Compared with the traditional method of predicting the formation pressure according to the accuracy of seismic data or the data of adjacent wells, the formation pressure predicted by the formation pressure monitoring method of the present invention by obtaining the logging while drilling parameters will be more accurate. Considering that there are multiple sources of abnormal pressure formation mechanism, this method analyzes the outlet temperature slope and establishes the corresponding relationship between the outlet temperature slope and the formation pressure trend, so as to achieve the purpose of quantitatively monitoring the formation pressure through the change of the outlet temperature slope, provide the drilling construction party with a basis for adjusting the drilling fluid, avoid construction risks, and improve the drilling speed. The device of the embodiment of the present invention can monitor the change of formation pressure in real time, so as to predict the existence of abnormal high pressure in advance, so as to achieve the purpose of early warning.

[0083] Unless otherwise specifically stated, terms such as processing, computing, calculating, determining, displaying, etc. may refer to the actions and / or processes of one or more processing or computing systems, or similar devices, which operate and convert data represented as physical (e.g., electronic) quantities within registers or memories of a processing system into other data similarly represented as physical quantities within memories, registers, or other such information storage, transmission, or display devices of the processing system. Information and signals may be represented using any of a variety of different techniques and methods. For example, data, instructions, commands, information, signals, bits, symbols, and chips mentioned throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, light fields or particles, or any combination thereof.

[0084] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process can be rearranged without departing from the scope of protection of the present disclosure. The attached method claims present the elements of the various steps in an exemplary order and are not intended to be limited to the specific order or hierarchy described.

[0085] In the above detailed description, various features are grouped together in a single embodiment to simplify the disclosure. This method of disclosure should not be interpreted as reflecting an intention that the embodiments of the claimed subject matter require more features than are clearly stated in each claim. On the contrary, as reflected in the appended claims, the invention is in a state of having less than all the features of the disclosed individual embodiments. Therefore, the appended claims are hereby expressly incorporated into the detailed description, with each claim standing on its own as a separate preferred embodiment of the invention.

[0086] Those skilled in the art will also appreciate that the various illustrative logic blocks, modules, circuits, and algorithmic steps described in conjunction with the embodiments herein can all be implemented as electronic hardware, computer software, or a combination thereof. In order to clearly illustrate the interchangeability between hardware and software, various illustrative components, blocks, modules, circuits, and steps are generally described above around their functions. Whether such functions are implemented as hardware or software depends on specific applications and the design constraints imposed on the entire system. A skilled person can implement the described functions in an alternative manner for each specific application, but such implementation decisions should not be interpreted as departing from the scope of protection of the present disclosure.

[0087] The steps of the method or algorithm described in conjunction with the embodiments herein may be directly embodied as hardware, a software module executed by a processor, or a combination thereof. The software module may be located in a RAM memory, a flash memory, a ROM memory, an EPROM memory, an EEPROM memory, a register, a hard disk, a mobile disk, a CD-ROM, or any other form of storage medium well known in the art. An exemplary storage medium is connected to the processor so that the processor can read information from the storage medium and can write information to the storage medium. Of course, the storage medium may also be an integral part of the processor. The processor and the storage medium may be located in an ASIC. The ASIC may be located in a user terminal. Of course, the processor and the storage medium may also be present in a user terminal as discrete components.

[0088] For software implementation, the techniques described in this application can be implemented with modules (e.g., procedures, functions, etc.) that perform the functions described in this application. These software codes can be stored in a memory unit and executed by a processor. The memory unit can be implemented within the processor or outside the processor. In the latter case, it is coupled to the processor in a communication manner via various means, which are well known in the art.

[0089] The above description includes examples of one or more embodiments. Of course, it is impossible to describe all possible combinations of components or methods for the purpose of describing the above embodiments, but it should be recognized by those skilled in the art that the various embodiments may be further combined and arranged. Therefore, the embodiments described herein are intended to cover all such changes, modifications and variations that fall within the scope of protection of the appended claims. In addition, with respect to the term "comprising" used in the specification or claims, the word is covered in a manner similar to the term "including", just as "including," is explained as a transitional word in the claims. In addition, any term "or" used in the specification of the claims is intended to mean "non-exclusive or".

Claims

1. A method for monitoring formation pressure while drilling, It is characterized in that include: Obtaining logging while drilling parameters of at least one normal pressure well section in the drilled well section of the well to be monitored, and determining a first drilling fluid outlet temperature slope of the normal pressure well section according to the logging while drilling parameters of the normal pressure well section; Obtaining logging while drilling parameters of the current drilling section of the well to be monitored, and determining the second drilling fluid outlet temperature slope of the current drilling section according to the logging while drilling parameters of the current drilling section; Determining a change in formation pressure coefficient according to the first drilling fluid outlet temperature slope and the second drilling fluid outlet temperature slope; Whether the formation pressure is normal is determined based on the change in the formation pressure coefficient and a preset threshold for the change in the formation pressure coefficient.

2. The method according to claim 1, It is characterized in that The method of obtaining the logging while drilling parameters of at least one normal pressure well section in the drilled well section of the well to be monitored, and determining the first drilling fluid outlet temperature slope of the normal pressure well section according to the logging while drilling parameters of the normal pressure well section, comprises: Obtaining drilling fluid temperature data and corresponding well depth data in the logging while drilling parameters of a normal pressure well section in the drilled section of the well to be monitored; determining the first drilling fluid outlet temperature slope of the normal pressure well section according to the obtained drilling fluid temperature data and corresponding well depth data in the logging while drilling parameters of the normal pressure well section; or The drilling fluid temperature data and corresponding well depth data in the logging while drilling parameters of at least two normal pressure well sections in the drilled section of the well to be monitored are obtained; the first drilling fluid outlet temperature slope of each normal pressure well section is determined according to the drilling fluid temperature data and the corresponding well depth data in the logging while drilling parameters of each normal pressure well section; the first drilling fluid outlet temperature slope of each normal well section is weighted averaged to obtain the first drilling fluid outlet temperature slope of the normal pressure well section.

3. The method according to claim 2, It is characterized in that The method of determining the first drilling fluid outlet temperature slope of each normal pressure well section according to the drilling fluid temperature data and the corresponding well depth data in the logging while drilling parameters of each normal pressure well section comprises: The first drilling fluid outlet temperature slope in the normal pressure well section is determined using the following formula: Among them, k t1 is the first drilling fluid outlet temperature slope, t max1 and t min1 are the maximum and minimum drilling fluid outlet temperatures of the drilled normal pressure well section, respectively. t max1 The corresponding well depth, t min1 The corresponding well depth, where Greater than 4. The method according to claim 1, It is characterized in that The method of obtaining the logging while drilling parameters of the current drilling section of the well to be monitored and determining the second drilling fluid outlet temperature slope of the current drilling section according to the logging while drilling parameters of the current drilling section includes: Obtain the drilling fluid outlet temperature and the corresponding well depth of the well section currently being drilled, and determine the second drilling fluid outlet temperature slope according to the following formula: Among them, k t2 is the second drilling fluid outlet temperature slope, t max2 and t min2 are the maximum and minimum drilling fluid outlet temperatures of the well section being drilled, respectively. t max2 The corresponding well depth, t min2 The corresponding well depth, where Greater than 5. The method according to claim 1, It is characterized in that Determining a change in formation pressure coefficient according to the first drilling fluid outlet temperature slope and the second drilling fluid outlet temperature slope includes: The formation pressure variation coefficient is determined by the following formula: Where Δt is the formation pressure variation coefficient, k t1 is the first drilling fluid outlet temperature slope, k t2 is the second drilling fluid outlet temperature slope; According to the determined formation pressure variation coefficient, the formation pressure coefficient variation is obtained.

6. The method according to claim 1, wherein the formation pressure is determined to be normal according to the change of the formation pressure coefficient and a preset threshold value of the change of the formation pressure coefficient. include: If the formation pressure coefficient is less than a preset formation pressure coefficient change threshold, it is determined that the formation pressure is normal; If the formation pressure coefficient is not less than a preset formation pressure coefficient change threshold, the formation pressure is determined to be abnormal.

7. The method according to claim 6, It is characterized in that Also includes: After determining that the formation pressure is abnormal based on the formation pressure coefficient change and the preset formation pressure coefficient change threshold, the user is immediately prompted to stop drilling and / or adjust the drilling fluid parameters.

8. The method according to claim 1, It is characterized in that Also includes: Periodically obtain changes in formation pressure coefficient at preset time intervals; If it is determined that the formation pressure is normal based on the change in the formation pressure coefficient, the drilling work is performed normally; If the formation pressure is determined to be abnormal based on the change in the formation pressure coefficient, an abnormal pressure warning message is sent.

9. A formation pressure monitoring device while drilling, It is characterized in that include: A data acquisition module, used to obtain logging parameters while drilling of at least one normal pressure well section in the drilled well section of the well to be monitored; and obtaining the logging while drilling parameters of the current drilling section of the well to be monitored; The data processing module is used to determine the first drilling fluid outlet temperature slope of the normal pressure well section according to the logging parameters of the normal pressure well section; determine the second drilling fluid outlet temperature slope of the current drilling well section according to the logging parameters of the current drilling well section; The pressure monitoring module determines the change of the formation pressure coefficient according to the first drilling fluid outlet temperature slope and the second drilling fluid outlet temperature slope; and determines whether the formation pressure is normal according to the change of the formation pressure coefficient and a preset formation pressure coefficient change threshold.

10. A computer storage medium, It is characterized in that The computer storage medium stores computer executable instructions, and when the computer executable instructions are executed by the processor, the method for monitoring formation pressure while drilling described in any one of claims 1-8 is implemented.

11. A computer device, It is characterized in that include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method for monitoring formation pressure while drilling as described in any one of claims 1 to 8 when executing the program.

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