Rock electrical parameter test clamping device and test method

Abstract

The invention belongs to the technical field of petroleum and natural gas engineering, and discloses a rock electrical parameter test clamping device and a test method.The device comprises a plug A, a rubber sleeve and a plug B. The plug A and the plug B are installed at the two ends of the rubber sleeve correspondingly, and a plurality of semi-annular grooves are formed in the rubber sleeve and parallel to the end face of the rubber sleeve; the lower parts of the conductive half-shaped clamp A, the conductive half-shaped clamp B and the conductive half-shaped clamp C are semi-ring-shaped and are arranged in the grooves of the rubber cylinder, the outer diameter end surfaces of the conductive half-shaped clamp A, the conductive half-shaped clamp B and the conductive half-shaped clamp C are provided with straight rods and extend out of the rubber cylinder, the longitudinal sections of the plugs A and B are T-shaped, screw holes are formed in two sides, the upper side surfaces and the lower end surfaces of the plugs A are provided with L-shaped small holes for communicating, and the upper end surface of the plug A is provided with a wire. According to the invention, the problems of uneven resistance, large error and the like caused by uneven end face in rock core end face testing are avoided, and the accuracy of rock electrical parameter testing is improved; the testing process is more flexible and reliable, and the precision of well logging evaluation and interpretation of rock physical property parameters is further improved.

Description

Technical Field

[0001] The invention belongs to the technical field of petroleum and natural gas engineering, and in particular relates to a rock electrical parameter test clamping device and a test method. Background Art

[0002] The traditional method of obtaining rock electrical parameters uses cores from different coring locations to measure the resistivity changes at both ends of the core during the displacement process to obtain rock electrical parameters. Then, all cores are fitted to obtain a set of rock electrical parameters. The fitting formula is as follows:

[0003]

[0004]

[0005] Where:

[0006] R o —100% saturated formation water rock resistivity, Ω·m;

[0007] R w — formation water resistivity, Ω·m;

[0008] Φ—effective porosity of rock;

[0009] a—lithology coefficient related to lithology;

[0010] m—cementation index;

[0011] F—stratigraphic factors;

[0012] R t —True resistivity of rock, Ω·m;

[0013] b—coefficient related to lithology;

[0014] n—saturation index;

[0015] S w — rock water saturation;

[0016] I—resistance increase coefficient.

[0017] In the process of implementing the present invention, the prior art still has the following problems:

[0018] The core to be tested needs to be processed into a specified cylindrical shape. When the end face is cut, the end face of shale and fine sandstone cores is very easy to break. After manual or machine processing, it is placed in a conventional clamp and clamped on both sides. Due to the low axial compressive and shear strength of the core, the end face of the core often breaks during the pressure application process, resulting in large errors in the rock electrical parameter test. In addition, the rock electrical parameter test process is cumbersome and the test time is long. The core must be replaced for each test, and the rock electrical parameters of different small sections of the core cannot be tested continuously. Summary of the invention

[0019] The present invention provides a rock electrical parameter test clamping device and a test method to solve the problems existing in the above-mentioned background technology, such as the core pressurized end face is easy to break, the test error is large, and continuous testing cannot be performed. The evaluation of rock physical property parameters is an important link in the field of oil and gas engineering technology. Accurate rock electrical parameters provide a basis for the calculation of reservoir oil saturation and permeability in comprehensive logging interpretation, and improve the accuracy of logging evaluation and interpretation of rock physical property parameters.

[0020] To achieve the above object, the present invention provides the following technical solutions:

[0021] A rock electrical parameter testing clamping device comprises a plug A, a rubber tube and a plug B. Plug A and plug B are respectively installed at both ends of the rubber tube. The rubber tube has a plurality of semi-circular grooves inside and parallel to the end face of the rubber tube. The lower parts of the conductive half-clip A, the conductive half-clip B and the conductive half-clip C are semi-circular and arranged in the grooves of the rubber tube. The outer diameter end faces thereof are provided with straight rods extending out of the rubber tube. The longitudinal cross-sections of the plugs A and B are T-shaped and have screw holes on both sides. The upper side faces thereof are connected to the lower end faces with L-shaped small holes. The upper end face of the plug A is provided with a wire.

[0022] Preferably, the rubber sleeve is made of silicone rubber or fluorine rubber.

[0023] Preferably, the conductive half-clip A, the conductive half-clip B and the conductive half-clip C are made of silver or copper.

[0024] Preferably, sealing rings are provided between the plug A and the rubber sleeve, and between the plug B and the rubber sleeve.

[0025] Preferably, the inner diameters of the conductive half-shaped clip A, the conductive half-shaped clip B and the conductive half-shaped clip C are greater than or equal to the inner diameter of the rubber cylinder.

[0026] Preferably, a semi-annular groove is provided on the lower end surface of the plug A and the plug B and is connected to the L-shaped small hole.

[0027] A method for testing rock electrical parameters, the steps are as follows:

[0028] After vacuuming, put the core into a container filled with simulated water, and submerge the core in simulated water to form a core saturated with simulated water. Record its weight, put the saturated simulated water core into a rubber cylinder, install plugs A and B at both ends of the rubber cylinder, and seal the core. Connect the conductive semi-annular clamp A to the positive pole of the resistor, and connect the conductive semi-annular clamp B and conductive semi-annular clamp C to the negative pole of the resistor respectively. Put the rock electrical parameter test holder into a sealed container filled with silicone oil and heat and increase the pressure; connect the inlet end of the L-shaped small hole of plug A to the intermediate container filled with simulated oil, and connect the outlet end of the L-shaped small hole of plug B to the micro-metering tube to adjust the flow of the horizontal flow pump. The simulated oil in the middle container is introduced into the core at a uniform speed to displace the simulated water in the core. The resistance value of the conductive semi-annular clamp A and the conductive semi-annular clamp B, and the conductive semi-annular clamp A and the conductive semi-annular clamp C are tested by the resistance instrument every 10 minutes and recorded. The simulated water flows into the micro-metering tube from the L-shaped hole of the plug B, and the volume of the water in the micro-metering tube is read. When the simulated oil appears in the micro-metering tube, the test process is completed, and the test data are sorted out for fitting to obtain the rock electrical parameters of the core between the conductive semi-annular clamp A and the conductive semi-annular clamp B, and the rock electrical parameters of the core between the conductive semi-annular clamp A and the conductive semi-annular clamp C.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows: a rock electrical parameter test clamping device and a test method are provided, in which a plurality of semi-annular clamps parallel to the end face of the rubber tube are installed, and the semi-annular clamps are pressed against the side surface of the core when the ring pressure is applied, thereby avoiding the problems of uneven resistance and large error caused by the uneven end face of the core end face test, and improving the accuracy of the rock electrical parameter test; through a plurality of parallel annular clamps, continuous testing of the rock electrical parameters of different small sections of the core is achieved, the test process is more flexible and reliable, and the accuracy of the logging evaluation and interpretation of the rock physical parameters is further improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A top view of a rock electrical parameter test clamping device and a clamp required for a test method of the present invention;

[0031] Figure 2 A longitudinal cross-sectional view of a clamp required for a rock electrical parameter test clamping device and a test method of the present invention;

[0032] Figure 3 It is a front view of a plug A in a clamp required for a rock electrical parameter test clamping device and a test method of the present invention;

[0033] Figure 4 A longitudinal cross-sectional view of a plug A in a clamp required for a rock electrical parameter test clamping device and a test method of the present invention;

[0034] Figure 5 It is a front view of a plug B in a clamp required for a rock electrical parameter test clamping device and a test method of the present invention;

[0035] Figure 6 It is a lower end view of plug A and plug B in a clamp required for a rock electrical parameter test clamping device and a test method of the present invention;

[0036] Figure 7 It is a side view of a rubber cylinder and a conductive semi-annular clamp in a clamp required for a rock electrical parameter test clamping device and a test method of the present invention;

[0037] Figure 8 It is a front view of a semi-annular clamp in a clamp required for a rock electrical parameter test clamping device and a test method of the present invention;

[0038] Fig. 9 This is a relationship diagram between formation factors and porosity tested by a rock electrical parameter testing clamping device and testing method of the present invention.

[0039] In the accompanying drawings: 1-plug A, 2-rubber cylinder, 3-conductive semi-annular clamp A, 4-conductive semi-annular clamp B, 5-conductive semi-annular clamp C, 6-plug B, 101-screw hole, 102-conducting wire, 103-L-shaped small hole, 104-semi-annular groove. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] In the description of the present invention, it should be noted that the terms "upper", "lower", "inside" and "outside" etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction; the term "connection" is understood to be connected by a capillary or fixed connection, and therefore cannot be understood as a limitation on the present invention.

[0042] Please refer to the instruction manual Figure 1-9The present invention provides a technical solution: a rock electrical parameter test clamping device and a test method, comprising a plug A1, a rubber tube 2, and a plug B6. The plug A1 and the plug B6 are respectively installed at both ends of the rubber tube 2. The rubber tube 2 has a plurality of semi-circular grooves 104 inside and is parallel to the end face of the rubber tube 2. The lower part of the conductive semi-circular clamp A3, the conductive semi-circular clamp B4, and the conductive semi-circular clamp C5 is semi-circular and arranged in the groove of the rubber tube 2. The outer diameter end face thereof has a straight rod extending out of the rubber tube 2. The longitudinal cross-section of the plug A1 and the plug B6 is T-shaped, with screw holes 101 on both sides, and the upper side surface thereof is connected with the lower end face by an L-shaped small hole 103, and the upper end face of the plug A1 has a wire 102. The rubber tube 2 is made of silicone rubber, the length of the rubber tube 2 is 10 cm, and the inner diameter thereof is 2.5 cm. The conductive semi-circular clamp A3, the conductive semi-circular clamp B4, and the conductive semi-circular clamp C5 are made of silver. Sealing rings are arranged between plug A1 and rubber tube 2, plug B6 and rubber tube 2. The inner diameters of conductive semi-annular clamps A3, B4 and C5 are equal to the inner diameter of rubber tube 2. Semi-annular grooves 104 are arranged on the lower end surfaces of plugs A1 and B6 and communicate with L-shaped small holes 103.

[0043] Embodiment 1:

[0044] In this embodiment, the core is the core of the core well in Dehui area of ​​Jilin Oilfield, which is processed and cut into a cylindrical core with a length of 6 cm and a diameter of 2.5 cm, an air permeability of 347 mD, and a weight of 50.7 g. The simulated oil is prepared by mixing the crude oil and kerosene in the reservoir of Dehui area of ​​Jilin Oilfield in a ratio of 1:3, and the viscosity is 9.72 mPa·s at 45°C. The oily wastewater produced by the reservoir in Dehui area of ​​Jilin Oilfield is filtered to obtain simulated water for standby use.

[0045] First, a vacuum pump was used to evacuate the core at -0.1 MPa for 120 h. After evacuation, the core was placed in a container filled with simulated water to immerse the core in simulated water. Under a pressure of 12 MPa, the core was immersed in simulated water for 12 h to form a core saturated with simulated water. The weight of the core was measured to be 58.4 g.

[0046] Place the saturated simulated water core into the rubber tube 2, install the plug A1 and plug B6 at both ends of the rubber tube 2, and seal the core. Connect the conductive semi-annular clamp A3 to the positive pole of the resistor, and connect the conductive semi-annular clamp B4 and conductive semi-annular clamp C5 to the negative pole of the resistor. Place the rock electrical parameter test holder into a sealed container filled with silicone oil and heat it to 45°C. Add silicone oil to the sealed container and increase the pressure to 7.6MPa.

[0047] The inlet end of the L-shaped hole 103 of the plug A1 is connected to an intermediate container filled with simulated oil, and the outlet end of the L-shaped hole 103 of the plug B6 is connected to a micro-metering tube. The flow rate of the horizontal flow pump is adjusted to 0.2mL / h to uniformly move the simulated oil in the intermediate container into the core, and the simulated oil displaces the simulated water in the core. Every 10 minutes, the resistance instrument tests the resistance values ​​of the conductive semi-annular clamp A3 and the conductive semi-annular clamp B4, and the conductive semi-annular clamp A3 and the conductive semi-annular clamp C5, and records them. Simulated water flows into the micro-metering tube from the L-shaped hole 103 of the plug B6, and the volume of water in the micro-metering tube is read. When simulated oil appears in the micro-metering tube, the test process is completed, and the test data is sorted out for fitting to obtain the rock electrical parameters of the core between the conductive semi-annular clamp A3 and the conductive semi-annular clamp B4, and the rock electrical parameters of the core between the conductive semi-annular clamp A3 and the conductive semi-annular clamp C5. The obtained rock electrical parameters of the core between the conductive semi-annular clamp A3 and the conductive semi-annular clamp C5 are as shown in the attached manual. Fig. 9 shown.

[0048] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A rock electrical parameter test clamping device, characterized in that: The invention comprises a plug A (1), a rubber tube (2) and a plug B (6). The plug A (1) and the plug B (6) are respectively installed at both ends of the rubber tube (2). The rubber tube (2) has a plurality of semi-circular grooves (104) inside and parallel to the end surface of the rubber tube. The lower parts of the conductive half-shaped clips A (3), the conductive half-shaped clips B (4) and the conductive half-shaped clips C (5) are semi-circular and arranged in the grooves of the rubber tube (2). The outer diameter end surfaces thereof have straight rods extending out of the rubber tube (2). The longitudinal cross-sections of the plugs A (1) and the plug B (6) are T-shaped and have screw holes (101) on both sides. The upper side surfaces thereof are connected to the lower end surfaces by L-shaped small holes (103). The upper end surface of the plug A (1) has a wire (102).

2. The rock electrical parameter test clamping device according to claim 1, characterized in that: The rubber cylinder (2) is made of silicone-containing rubber or fluorine-containing rubber.

3. The rock electrical parameter test clamping device according to claim 1, characterized in that: The conductive half-clip A (3), the conductive half-clip B (4) and the conductive half-clip C (5) are made of silver or copper.

4. The rock electrical parameter test clamping device according to claim 1, characterized in that: Sealing rings are arranged between the plug A (1) and the rubber sleeve (2), and between the plug B (6) and the rubber sleeve (2).

5. The rock electrical parameter test clamping device according to claim 1, characterized in that: The inner diameters of the conductive half-shaped clamp A (3), the conductive half-shaped clamp B (4) and the conductive half-shaped clamp C (5) are greater than or equal to the inner diameter of the rubber sleeve (2).

6. The rock electrical parameter test clamping device according to claim 1, characterized in that: A semi-annular groove (104) is provided on the lower end surface of the plug A (1) and the plug B (6) and is communicated with the L-shaped small hole (103).

7. A method for testing rock electrical parameters, characterized in that: Here are the steps: After vacuuming, the core is placed in a container filled with simulated water, and the simulated water immerses the core to form a core saturated with simulated water. The weight of the core is recorded, and the saturated simulated water core is placed in a rubber tube (2). Plugs A (1) and plugs B (6) are installed at both ends of the rubber tube (2) to seal the core. The conductive semi-annular clamp A (3) is connected to the positive pole of the resistor, and the conductive semi-annular clamp B (4) and conductive semi-annular clamp C (5) are respectively connected to the negative pole of the resistor. The rock electrical parameter test holder is placed in a sealed container filled with silicone oil and heated and pressurized. The inlet end of the L-shaped small hole (103) of the plug A (1) is connected to an intermediate container filled with simulated oil, and the outlet end of the L-shaped small hole (103) of the plug B (6) is connected to a micro-metering tube to adjust the horizontal flow. The simulated oil in the intermediate container is pumped into the core at a uniform flow rate, and the simulated oil displaces the simulated water in the core. Every 10 minutes, the resistance instrument tests the resistance values ​​of the conductive semi-annular clamp A (3) and the conductive semi-annular clamp B (4), and the conductive semi-annular clamp A (3) and the conductive semi-annular clamp C (5), and records them. The simulated water flows into the micro-metering tube from the L-shaped small hole (103) of the plug B (6), and the volume of the water in the micro-metering tube is read. When the simulated oil appears in the micro-metering tube, the test process is completed, and the test data are sorted and fitted to obtain the rock electrical parameters of the core between the conductive semi-annular clamp A (3) and the conductive semi-annular clamp B (4), and the rock electrical parameters of the core between the conductive semi-annular clamp A (3) and the conductive semi-annular clamp C (5).

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