Plugging performance evaluation instrument for drilling fluid

Abstract

The utility model provides a plugging performance evaluation instrument for drilling fluid, which comprises a hydraulic pump, and the outlet end of the hydraulic pump is connected with a hydraulic assembly through a pipe group and is communicated with a drilling fluid tank through a hose of the hydraulic assembly; a temperature controller used in cooperation with the heating sleeve is arranged on the heating sleeve, and a heating switch is arranged on the heating sleeve. A back pressure receiver is installed on the outer wall of the top end face of the heating sleeve, the back pressure receiver is connected with a communicating pipe through a quick connecting piece, multiple sets of pressure regulating valves are arranged on the communicating pipe, and first pressure gauges are arranged on the pressure regulating valves. According to the plugging performance evaluation instrument, the matching degree of plugging agent particles and the stratum can be evaluated more truly, the plugging performance of drilling fluid on the stratum can be reflected, and then safe and reliable plugging testing can be guaranteed.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the plugging technical field for drilling fluid, especially relates to a plugging performance evaluation appearance for drilling fluid. BACKGROUND

[0002] For the stratum with developed bedding and fissure, in order to prevent the well collapse and leakage of stratum, reduce the damage to oil and gas layer, the drilling fluid is required to have strong plugging property, effectively seals the stratum bedding and fissure, prevents the drilling fluid and filtrate from entering the stratum, and achieves the purpose of improving the stratum pressure bearing capacity, stabilizing the well wall, preventing the well leakage and protecting the oil and gas layer.

[0003] The essence of the plugging property of drilling fluid refers to improving the density (reducing the permeability) of the well wall annulus through the dynamic contact between the drilling fluid and the well wall under certain temperature and pressure conditions, so as to reduce the filtrate invasion depth and pressure transmission speed.

[0004] The plugging includes physical plugging and chemical plugging in mechanism. The physical plugging is realized by forming relatively dense inner filter cake and outer filter cake by adhering the reasonable solid phase particles to the well wall.

[0005] The physical plugging effect of drilling fluid: under certain pressure conditions, the drilling fluid penetrates into the well wall, at the same time, part of the solid phase material deposits in the pores or fissures of the well wall and forms the inner filter cake, thereby reducing the permeability of the near well wall; and the other part of the solid phase material is blocked outside the well wall and forms the outer filter cake.

[0006] The essence of the physical plugging technology of drilling fluid is to reduce the filtrate invasion depth through the joint action of the inner filter cake and the outer filter cake, which is the same as the purpose of reducing the filtration loss.

[0007] The plugging technology of drilling fluid is an important index of the performance evaluation of drilling fluid, and is related to the wellbore stability and reservoir protection. However, there is lack of professional plugging performance evaluation instrument for drilling fluid, which leads to the inability to perform safe and reliable plugging test.

[0008] Therefore, how to solve the defects in the prior art has become one of the problems to be solved in the plugging technical field for drilling fluid. CONTENT OF THE UTILITY MODEL

[0009] In view of the problems in the background art, the utility model provides a plugging performance evaluation instrument for drilling fluid, which comprises,

[0010] A hydraulic pump,

[0011] The outlet end of the hydraulic pump is connected with a hydraulic assembly through a pipe group, and the drilling fluid tank is communicated through the hose of the hydraulic assembly;

[0012] Also include a heating jacket, the heating jacket is provided with a temperature controller used in conjunction with it, the heating jacket is provided with a heating switch;

[0013] The top end face outer wall of the heating jacket is provided with a back pressure receiver, and the back pressure receiver is connected to a communication pipe through a quick connection connector, and a plurality of groups of pressure regulating valves are arranged on the communication pipe, and a first pressure gauge is arranged on the pressure regulating valve.

[0014] Optionally, the top cover and the bottom cover are arranged at the upper and lower ends of the drilling fluid tank body,

[0015] A second communication valve rod is arranged in the drilling fluid tank body at the position of the top cover, and a storage cavity for filling drilling fluid is communicated through the second communication valve rod,

[0016] A filter element is arranged in the drilling fluid tank body near the position of the second communication valve rod.

[0017] Optionally, a piston is further arranged in the storage cavity,

[0018] A first communication valve rod is arranged in the drilling fluid tank body near the position of the bottom cover.

[0019] Optionally, an air inlet pipe and an air outlet pipe are arranged on the back pressure receiver,

[0020] And a second pressure gauge for monitoring the change of internal air pressure of the back pressure receiver is further arranged on the back pressure receiver.

[0021] Optionally, the quick connection connector includes an outer pipe arranged on the back pressure receiver,

[0022] And a first variable-diameter limiting ring is arranged on the outer pipe in an integrated manner,

[0023] A plurality of thread holes uniformly distributed circumferentially are arranged on the first variable-diameter limiting ring.

[0024] Optionally, a knurled knob is arranged outside the outer pipe,

[0025] A fastening bolt located in the thread hole passes through a thread hole in the bottom end face of the knurled knob, and is threadedly connected,

[0026] A hollow screw is threadedly connected in the knurled knob,

[0027] The hollow screw is fixedly connected to an inner pipe through a second variable-diameter limiting ring.

[0028] Optionally, a protrusion is arranged on the outer wall of the inner pipe,

[0029] And a groove is formed in the inner wall of the second variable-diameter limiting ring for the protrusion to extend into, and is used in conjunction with, to be clamped and connected.

[0030] The second variable-diameter limiting ring is divided into upper and lower ends,

[0031] And the groove is located at the upper end of the second variable-diameter limiting ring;

[0032] The lower end of the second variable-diameter limiting ring is provided with a hollow screw rod integrated therewith.

[0033] Optionally, an opening is formed on the second variable-diameter limiting ring to divide the second variable-diameter limiting ring into two ends,

[0034] And a groove is formed on one end of the second variable-diameter limiting ring,

[0035] And a threaded hole in the groove is threadedly connected with a fastening bolt,

[0036] And the fastening bolt passes through the threaded hole and extends into a threaded hole on the second variable-diameter limiting ring at the other end to be fixedly connected.

[0037] In summary, the beneficial effects of the present application are:

[0038] (1) The plugging performance evaluation instrument can more truly evaluate the matching degree of the plugging agent particles and the formation, can reflect the plugging performance of the drilling fluid on the formation, and can further ensure safe and reliable plugging test.

[0039] (2) The present application has simple structure, can quickly assemble and disassemble the inner pipe and the outer pipe, when the inner pipe and the outer pipe need to be connected, at this time, only need to stretch the inner pipe into the second variable-diameter limiting ring, so that the protrusion of the inner pipe is clamped into the groove of the second variable-diameter limiting ring, and the fastening bolt is tightened, and then the connection between the second variable-diameter limiting ring and the inner pipe is realized; Then the fastening bolt passes through the threaded holes of the first variable-diameter limiting ring and the knurled knob from bottom to top in turn, and is threadedly fixedly connected; Then the fixed connection between the first variable-diameter limiting ring and the knurled knob is realized; Finally, the hollow screw rod is tightened in the knurled knob, and is threadedly connected, and then the connection between the outer pipe and the inner pipe is realized. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 It is a whole structure schematic view of one embodiment of the plugging performance evaluation instrument for drilling fluid of the present application;

[0041] Figure 2 It is a drilling fluid tank structure schematic view of one embodiment of the plugging performance evaluation instrument for drilling fluid of the present application;

[0042] Figure 3 It is a partial structure schematic view of one embodiment of the plugging performance evaluation instrument for drilling fluid of the present application;

[0043] Figure 4 Figure 1 is an assembly drawing of the outer pipeline and the inner pipeline of an embodiment of the plugging performance evaluation instrument for drilling fluid of the present application;

[0044] Figure 5 The present application is Figure 4 Figure 2 is a structural enlarged view of the A position in the middle.

[0045] Reference signs:

[0046] 10, hydraulic assembly; 101, hydraulic pipe;

[0047] 20, hydraulic pump;

[0048] 30, heating jacket; 301, heating switch;

[0049] 40, temperature controller;

[0050] 50, back pressure receiver; 501, air inlet pipe; 502, liquid outlet pipe; 503, second pressure gauge; 504, air outlet pipe; 505, quick connection connector; 5051, outer pipeline; 5052, first variable-diameter limiting ring; 5053, threaded hole; 5054, knurl knob; 5055, first sealing washer; 5056, second sealing washer; 5057, hollow screw rod;

[0051] 60, drilling fluid tank; 601, base; 602, bottom cover; 603, piston; 604, drilling fluid tank body; 605, storage cavity; 606, scale; 607, filter element; 608, top cover;

[0052] 701, first communication valve rod; 702, second communication valve rod;

[0053] 801, communication pipe; 803, first pressure gauge; 804, pressure regulating valve; 805, connecting inner pipe;

[0054] 90, second variable-diameter limiting ring; 901, groove body; 902, fastening bolt. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application will be further described in detail below with reference to the drawings and specific embodiments. Although the exemplary embodiments are disclosed in the drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to facilitate a more thorough understanding of the present application and to enable the complete disclosure of the concept of the present application to those skilled in the art.

[0056] In the description of the specification, the description of the terms "certain embodiments", "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine the different embodiments or examples described in the specification and the features of the different embodiments or examples without contradiction.

[0057] In the present application, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance; the term "a plurality of" means two or more, unless otherwise explicitly limited. The terms "mounting", "connection", "connection", "fixing" and the like should be understood in a broad sense, for example, "connection" can be fixed connection, or detachable connection, or integrally connected; "connected" can be directly connected, or indirectly connected through an intermediate medium. 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.

[0058] As shown in Figures 1-5 The present embodiment provides a plugging performance evaluation instrument for drilling fluid, comprising a hydraulic pump 20, and the outlet end of the hydraulic pump 20 is connected to a hydraulic assembly 10 through a pipe group, and the hydraulic assembly 10 is connected to a drilling fluid tank 60 through a hose;

[0059] The plugging performance evaluation instrument further comprises a heating jacket 30, and the heating jacket 3 is provided with a temperature controller 40 used in cooperation therewith, the temperature controller 40 is preferably a temperature control device of KSD series, and the heating jacket 3 is provided with a heating switch 301;

[0060] The heating jacket 30 is provided with a back pressure receiver 50 on the top end face outer wall thereof and fixedly connected by means of fastening screws or the like, the back pressure receiver 50 is connected to a communication pipe 801 through a quick connecting piece 505, a plurality of pressure regulating valves 804 are arranged on the communication pipe 801, and a first pressure gauge 803 is arranged on the pressure regulating valve 804.

[0061] In the present embodiment, those skilled in the art should understand that the plugging performance evaluation instrument of the present application can more truly evaluate the matching degree of the plugging agent particles and the formation, can reflect the plugging performance of the drilling fluid to the formation, and can further ensure safe and reliable plugging test.

[0062] Further, the drilling fluid tank body 604 is provided with a top cover 608 and a bottom cover 602 at the upper and lower ends thereof respectively, and a second communication valve rod 702 is arranged in the drilling fluid tank body 604 at the position of the top cover 608, and the storage cavity 605 is communicated through the second communication valve rod 702, and a filter core 607 is arranged in the drilling fluid tank body 604 close to the position of the second communication valve rod 702;

[0063] The storage cavity 605 is used to fill drilling fluid, and a piston 603 is further arranged in the storage cavity 605,

[0064] The drilling fluid tank body 604 close to the position of the bottom cover 602 is provided with a first communication valve rod 701.

[0065] In the embodiment, those skilled in the art can understand that when the drilling fluid tank 60 and the heating sleeve need to be assembled, the following steps can be performed:

[0066] 1. The piston is screwed in by a T-shaped wrench, and the piston 603 is installed in the drilling fluid tank body. In order to ensure that the piston can move freely, the lines on the T-shaped wrench need to be aligned with the top of the top cover 608, and then the T-shaped wrench is unscrewed from the piston 603;

[0067] 2. The space between the threads at the end of the drilling fluid tank close to the bottom cover and the piston is filled with hydraulic oil;

[0068] 3. The threaded cover is screwed in, and a two-pin nut wrench is used to tighten it. It should not be too tight, so that the hydraulic oil flows out of the bottom cover threaded hole, indicating that there is no gas between the piston and the bottom cover;

[0069] 4. Then the second communication valve rod 702 is installed and tightened;

[0070] 5. The other end of the drilling fluid tank top cover is placed upward, and the drilling fluid stirred for 10 minutes is added to the position of the scale of the drilling fluid tank body;

[0071] 6. The treated filter core is placed, the top cover is screwed in, and a two-pin nut wrench is used to tighten it;

[0072] 7. Then the first communication valve rod is screwed in;

[0073] 8. The drilling fluid tank at the end of the top cover is moved upward into the heating sleeve, and is rotated so that the positioning pin at the bottom of the heating sleeve is seated in the hole at the bottom of the drilling fluid tank body, and the thermometer is inserted;

[0074] 9. Finally, the hose of the hydraulic assembly is connected to the second communication valve rod, and the back pressure receiver is connected to the first communication valve rod, and is fixed with a locking pin, thereby completing the connection between the drilling fluid tank and the heating sleeve.

[0075] To complete the connection between the drilling fluid tank and the heating jacket, and when plugging test is needed, first connect the heating jacket 30 to the corresponding power supply, heat the heating jacket to 10°F (6°C) higher than the selected test temperature, and keep the temperature constant during the entire test process by using a temperature controller;

[0076] Next, stir the sample for 10 min;

[0077] Check the valve stems (first and second communication valve stems), the piston, the sealing rings on the drilling fluid tank and the top cover, replace the damaged or brittle sealing rings, and apply high temperature grease to all the sealing rings. After the experiment at a temperature above 150°C (300°F), all the sealing rings should be routinely replaced;

[0078] Then, the filter element is treated, which preferably has a filtration area of 22.6 cm2 (3.5 in2) and various pore sizes. In addition, metal sealing plates and abrasive discs can also be used as filter elements, but the abrasive discs cannot be reused;

[0079] Next, heating is performed. When the test temperature exceeds 93°C (225°F), refer to the back pressure value corresponding to the test temperature in Table 1, and use the hydraulic pump to apply the pressure to the drilling fluid tank; (Note: when doing experiments above 100°C, 0.5 MPa pressure heating is required.)

[0080] Because the closed drilling fluid tank is placed in the heating jacket, the thermal expansion of the substances in the drilling fluid tank and the hydraulic oil will cause the pressure in the drilling fluid tank to be too high. Therefore, when the drilling fluid tank at room temperature is placed in the hot heating jacket, the hydraulic pump 20 must be quickly connected to discharge the hydraulic fluid. Those skilled in the art will understand that during heating, the excess pressure should be discharged periodically to control the pressure in the drilling fluid tank, and the heating time should not exceed 1 h.

[0081] When the temperature of the sample in the drilling fluid tank reaches the required temperature, apply the working pressure and back pressure (see Table 1) to the sample in the drilling fluid tank, with a differential pressure of 1000 PSI;

[0082] Open the external nitrogen cylinder master valve, and at the same time open the T-shaped valve on the back pressure receiver valve stem (note that the space between the filter element and the back pressure collector outlet and the valve must be filled with base fluid before starting the test);

[0083] Twist the first communication valve stem to start the test, and read the pressure in the drilling fluid tank through the first pressure gauge of the hydraulic pump;

[0084] The filtrate was collected in a graduated cylinder at 1 min, 2.5 min, 5 min, 7.5 min, 15 min, 25 min, and 30 min after the start of the experiment, and the collection time and volume were accurately recorded for plotting the filtrate volume versus the square root of time and calculating the results;

[0085] The valve was closed after 30 min, and the remaining filtrate in the back pressure receiver was discharged into the graduated cylinder and recorded;

[0086] After the test was completed, the instrument was disassembled.

[0087] Table 1: Initial and heated pressure of the drilling fluid tank at various experimental temperatures

[0088]

[0089] During the experiment, those skilled in the art should understand that, in order to verify whether the selected filter element is suitable, the filter element needs to be repeatedly tested to ensure the quality of the filter element.

[0090] Table 2 is the filter element repeatability test data:

[0091]

[0092]

[0093] In this embodiment, those skilled in the art should understand that, before the experiment, the filter element needs to be fully saturated with the base fluid, and the base fluid will be different according to the experimental solution used (fresh water, salt water, base oil, etc.), and the saturation method is to immerse the filter element in the base fluid until it is fully saturated. According to the experimental verification, 10 min of immersion can fully saturate, and the verification data are shown in Table 3:

[0094]

[0095] Further, the back pressure receiver 50 is provided with an air inlet pipe 501 and an air outlet pipe 504, and the back pressure receiver 50 is further provided with a second pressure gauge 503 for monitoring the change of the air pressure inside the back pressure receiver 50.

[0096] In actual application, since the connection between the traditional back pressure receiver and the communication pipe is mostly fixed connection (for example, welding connection), it is inconvenient to replace in actual application. In order to solve the above technical problems, please refer to Figures 1-5 As shown in the figure, the back pressure receiver 50 is provided with a quick connection piece 505, and the connecting inner pipe 805 of the communication pipe 801 is connected through the quick connection piece 505.

[0097] Further, the quick connector 505 comprises an outer pipe 501 arranged on the back pressure receiver 50, and the outer pipe 501 is provided with a first variable-diameter limiting ring 5052 arranged integrally thereon, and the first variable-diameter limiting ring 5052 is provided with a plurality of thread holes 5053 uniformly distributed in the circumferential direction thereof.

[0098] Further, the outer pipe 5051 is provided with an embossed knob 5054, a fastening bolt located in the thread hole 5053 passes through a thread hole in the bottom end face of the embossed knob 5054, and is threadedly connected, thereby realizing the connection between the first variable-diameter limiting ring 5052 and the embossed knob 5054.

[0099] Further, a hollow screw 5057 is threadedly connected in the embossed knob 5054, and the hollow screw 5057 is fixedly connected with the inner pipe 805 through a second variable-diameter limiting ring 90.

[0100] Further, the outer wall of the inner pipe 805 arranged integrally with the communication pipe 801 is provided with a protrusion, and the inner wall of the second variable-diameter limiting ring 90 is provided with a groove for the protrusion to extend into, and the two are matched for clamping connection, thereby realizing the connection between the inner pipe 805 and the second variable-diameter limiting ring 90.

[0101] Further, the second variable-diameter limiting ring 90 is divided into upper and lower end portions, and the groove is located in the upper end portion of the second variable-diameter limiting ring 90.

[0102] The lower end portion of the second variable-diameter limiting ring 90 is provided with a hollow screw 5057 arranged integrally thereon.

[0103] Further, the second variable-diameter limiting ring 90 is provided with an opening, so as to divide the second variable-diameter limiting ring 90 into two end portions, and the second variable-diameter limiting ring 90 of one of the end portions is provided with a groove 901, and a fastening bolt 902 is threadedly connected in a thread hole of the groove 901, and the fastening bolt 902 passes through the thread hole and extends into a thread hole in the second variable-diameter limiting ring 90 of the other end portion adjacent thereto, and is fixedly connected.

[0104] Further, a first sealing washer 5055 is arranged between the top portion of the embossed knob 5054 and the bottom portion of the second variable-diameter limiting ring 90, and a second sealing washer 5056 is arranged in the hollow screw 5057.

[0105] In the embodiment, when the inner pipe 805 and the outer pipe 5051 need to be connected, the inner pipe 805 is only needed to be inserted into the second variable-diameter limiting ring 90, so that the protrusion of the inner pipe is clamped into the groove of the second variable-diameter limiting ring, and the fastening bolt 902 is tightened, thereby realizing the connection between the second variable-diameter limiting ring and the inner pipe.

[0106] Then the fastening bolt is sequentially threaded from bottom to top through the threaded hole of the first variable-diameter limiting ring and the embossed knob 5054, and is fixedly connected in a threaded manner, thereby realizing the fixed connection between the first variable-diameter limiting ring and the embossed knob.

[0107] Finally, the hollow screw 5057 is screwed into the embossed knob 5054, and is connected in a threaded manner, thereby realizing the connection between the outer pipe and the inner pipe.

[0108] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, but are not limiting. Although the present application has been described in detail with reference to the embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the present application, and all should be covered in the scope of the claims of the present application.

Claims

1. A sealing performance evaluation instrument for drilling fluids, characterized in that, Comprising, a hydraulic pump, an outlet end of the hydraulic pump is connected to a hydraulic assembly through a pipe group, and a tank of drilling fluid is communicated through a hose of the hydraulic assembly; a heating jacket is further included, a temperature controller is arranged on the heating jacket and used in cooperation with the heating jacket, and a heating switch is arranged on the heating jacket; a back pressure receiver is mounted on an outer wall of a top end surface of the heating jacket, the back pressure receiver is connected to a communication pipe through a quick connection connector, a plurality of groups of pressure regulating valves are arranged on the communication pipe, and a first pressure gauge is arranged on the pressure regulating valves. 2.The plugging performance evaluation instrument for drilling fluid of claim 1, wherein, a top cover and a bottom cover are arranged on the upper and lower ends of the tank body of the drilling fluid tank, a second communication valve rod is arranged in the tank body of the drilling fluid tank at the position of the top cover, and a storage cavity for filling drilling fluid is communicated through the second communication valve rod, a filter element is arranged in the tank body of the drilling fluid tank near the position of the second communication valve rod. 3.The plugging performance evaluation instrument for drilling fluid of claim 2, wherein, a piston is further arranged in the storage cavity, a first communication valve rod is arranged on the tank body of the drilling fluid tank near the position of the bottom cover. 4.The plugging performance evaluation instrument for drilling fluid of claim 1, wherein, an air inlet pipe and an air outlet pipe are arranged on the back pressure receiver, and a second pressure gauge for monitoring the change of the internal air pressure of the back pressure receiver is further arranged on the back pressure receiver. 5.The plugging performance evaluation instrument for drilling fluid of claim 1, wherein, the quick connection connector comprises an outer pipe arranged on the back pressure receiver, a first variable-diameter limiting ring is arranged on the outer pipe in an integrated manner, a plurality of thread holes uniformly distributed along the circumferential direction of the first variable-diameter limiting ring are arranged on the first variable-diameter limiting ring. 6.The plugging performance evaluation instrument for drilling fluid of claim 5, wherein, a knurled knob is arranged outside the outer pipe, a fastening bolt arranged in the thread hole penetrates the thread hole in the bottom end surface of the knurled knob and is threadedly connected, a hollow screw is threadedly connected in the knurled knob, and an inner pipe is fixedly connected to the hollow screw through a second variable-diameter limiting ring. 7.The plugging performance evaluation instrument for drilling fluid of claim 6, wherein, a protrusion is arranged on the outer wall of the inner pipe, a groove is formed in the inner wall of the second variable-diameter limiting ring for the protrusion to extend into and be engaged with for clamping connection, the second variable-diameter limiting ring is divided into upper and lower end portions, the groove is located in the upper end portion of the second variable-diameter limiting ring, and a hollow screw is arranged on the lower end portion of the second variable-diameter limiting ring in an integrated manner. 8.The plugging performance evaluation instrument for drilling fluid of claim 7, wherein, an opening is formed in the second variable-diameter limiting ring to divide the second variable-diameter limiting ring into two end portions, a groove is formed in the second variable-diameter limiting ring of one of the two end portions, a fastening bolt is threadedly connected in the thread hole of the groove, and the fastening bolt penetrates the thread hole and extends into the thread hole of the second variable-diameter limiting ring of the other end portion adjacent to the one end portion for fixed connection.

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