Anti-sticking device for logging cable

Abstract

The utility model discloses an anti-sticking device for a logging cable, which belongs to the technical field of petroleum machinery and comprises a cable body and an anti-sticking clamping wire, and the anti-sticking clamping wire is tightly wound on the outer surface of the cable body along the spiral line direction. The anti-sticking device for the logging cable can reduce the contact area and contact time of the cable and the stratum in the contact process of the cable and the stratum, and reduces the sticking risk.

Description

Technical Field

[0001] The utility model belongs to the technical field of petroleum machinery, and particularly relates to a device for preventing a well logging cable from sticking or getting stuck. Background Art

[0002] During the logging process, the mud viscosity is high, and the logging instrument string stays in the open hole for a long time, which can easily cause the cable to be partially adsorbed to the well wall, resulting in cable sticking. In recent years, during the cable pressure measurement and sampling operation in Bohai Oilfield, the instrument needs to be stationary for a long time during the sampling operation. At the same time, as the well depth becomes deeper and deeper, the contact length between the cable and the formation increases, resulting in a gradual increase in the risk of cable sticking. Cable sticking occurs frequently, especially in high-angle wells and deep well operations. It is inevitable that keyways will be generated due to cable sliding, and the cable is more likely to get stuck in the keyway. If the cable is not properly unstuck after sticking, it will not only affect production, but also cause serious economic losses, and may even cause the wellbore to be scrapped. Therefore, it is necessary to take measures to reduce the probability of cable sticking. Summary of the invention

[0003] The utility model is proposed to solve the problems existing in the prior art, and its purpose is to provide a logging cable anti-sticking device which can reduce the contact area and contact time between the cable and the formation during the contact process between the cable and the formation, thereby reducing the risk of sticking.

[0004] In order to achieve the above-mentioned purpose, the technical solution of the utility model provides a device for preventing sticking and jamming of a logging cable, comprising a cable body. The logging cable also comprises: an anti-sticking and jamming wire which is tightly wound around the outer surface of the cable body along a spiral line direction.

[0005] As a further improvement of the utility model, the anti-sticking wire is spirally wound around the outer surface of the cable body in a clockwise direction.

[0006] As a further improvement of the utility model, the anti-sticking wire is a steel wire.

[0007] As a further improvement of the present invention, the ratio L of the length of the steel wire to the length of the cable body is 2.2, the number N of the steel wires is 3, and the spacing d between adjacent steel wires is 1.4 cm.

[0008] As a further improvement of the present invention, the diameter of the steel wire is 1 mm.

[0009] In a logging cable anti-sticking device provided by an embodiment of the utility model, the anti-sticking wire is tightly wound around the outer surface of the cable body along the spiral line direction, which can reduce the contact area between the cable and the formation during the contact between the cable and the formation, shorten the contact time between the cable and the formation, reduce the risk of cable sticking during pressure sampling operations in deep formations, and adapt to the deep logging operation mode under the new situation. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a structural schematic diagram of a logging cable anti-sticking device provided by an embodiment of the utility model;

[0011] Figure 2 It is a schematic diagram of a tensile force determination experiment provided by an embodiment of the utility model;

[0012] Figure 3 yes Figure 2 The relationship between different steel wire cable ratios and starting friction resistance in the experiment shown;

[0013] Figure 4 yes Figure 2 The relationship between different steel wire spacing and starting friction resistance in the experiment shown.

[0014] Including: 1. Cable body; 2. Anti-sticking wire; 3. Mud column; 4. Long hole; 5. Tensile tester. DETAILED DESCRIPTION

[0015] The present invention is described in detail below with reference to the accompanying drawings and embodiments. The embodiments described are only a part of the embodiments of the present invention, not all of them. 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.

[0016] The embodiment of the utility model provides a device for preventing a logging cable from sticking and getting stuck, comprising a cable body 1, and the logging cable further comprises an anti-sticking and getting stuck wire 2, which is tightly wound along a spiral line on the outer surface of the cable body 1. Referring to the principle that threaded drill bits can prevent sticking and getting stuck in drilling operations, in the device for preventing a logging cable from sticking and getting stuck, the anti-sticking and getting stuck wire 2 is tightly wound along a spiral line on the outer surface of the cable body 1, which can reduce the contact area between the cable and the formation during the contact process between the cable and the formation, shorten the contact time between the cable and the formation, reduce the risk of sticking and getting stuck, and improve the safety of the operation.

[0017] Preferably, the anti-sticking wire 2 is spirally wound around the outer surface of the cable body 1 in a clockwise direction. Since the cable body 1 is usually a double-armored cable in a clockwise direction, the anti-sticking wire 2 is spirally wound around the outer surface of the cable body 1 in a clockwise direction to prevent the cable from loosening.

[0018] In some embodiments, the anti-sticking wire 2 is a steel wire with a diameter of 1 mm. According to GBT343-1994 General Purpose Low Carbon Steel Wire, the anti-sticking wire 2 can be a general purpose low carbon steel wire with a diameter of 1 mm.

[0019] In a preferred embodiment, the ratio L of the steel wire length to the length of the cable body 1 is 2.2, the number of steel wires N is 3, and the spacing d between adjacent steel wires is 1.4 cm (hereinafter referred to as the "231 scheme"). When the 231 scheme is adopted, the probability of cable sticking is the lowest.

[0020] In the actual application process, in order to determine the optimal solution, that is, the solution that can meet the operational requirements and minimize the risk of logging cable sticking and reduce over-lifting tension, this logging cable anti-sticking device has three important influencing factors, including: the ratio of steel wire length to cable length L, the number of steel wires N, and the spacing d of the steel wires. Since the application effects of different parameter solutions vary greatly, it is necessary to determine the optimal parameters through fixed variable method experiments.

[0021] In order to unify the experimental standards, the applicant adopted the following experimental methods: Figure 2 As shown in the figure, in the experiment, a cylindrical mud column 3 fixed on the ground is used. The mud column 3 is 1 meter high and 1 meter in diameter. A long hole 4 is dug in the center for passing the cable through the mud column 3. After the cable is connected, mud of the same composition is poured into the long hole 4 to ensure that the mud column 3 is in full contact with the cable to simulate the situation where the cable slides into the keyway. One end of the cable is connected to a tension tester 5 to measure the starting friction when the cable is pulled. The starting friction measured at this time is equivalent to the tension generated by the sticking between the 1-meter cable and the formation when the downhole cable encounters sticking.

[0022] During the experiment, the applicant used 1, 2, and 3 steel wires respectively and conducted the experiment according to different steel wire to cable length ratios, such as Figure 3 As shown in the figure, it can be seen from the experimental data that as the length ratio of the steel wire to the cable gradually increases from 1.2 to 3.0, the starting friction resistance gradually decreases, but after reaching 2.2, the starting friction resistance increases. When the length ratio of the steel wire to the cable is 2.2, the lowest value of the starting friction force is 37.8N when using 3 steel wires.

[0023] like Figure 4 As shown in the figure, it is the relationship between different wire spacing and starting friction. From the experimental data, it can be seen that as the wire spacing increases, the starting friction resistance first gradually decreases; when the wire spacing is about 1.4cm, the starting friction reaches the minimum value; when the wire spacing exceeds 1.4cm, as the wire spacing increases, the starting friction gradually increases. This shows that in order to minimize the starting friction, the wire spacing should be kept at about 1.4cm.

[0024] Therefore, based on the previous experimental data analysis, the applicant determined the above 231 scheme.

[0025] In a specific embodiment, in order to verify whether the 231 scheme will produce stress concentration on the cable drum and cause the cable core to be squeezed, the applicant spirally wraps the steel wire that meets this parameter on the entire cable drum in a clockwise direction to observe whether it will affect the cable drum. The cables are arranged evenly and the cable core is not squeezed due to uneven force.

[0026] In some specific embodiments, by adopting the 231 scheme of the logging cable anti-sticking device, at least the following beneficial effects are achieved: (1) The risk of sticking can be reduced. In the actual sampling operation, the risk of sticking that originally existed after 5-7 hours of stillness is better alleviated after using this logging cable anti-sticking device, thereby reducing the risk of sticking. (2) The over-lifting tension during sticking can be reduced. In the actual operation process, when sticking occurs, it is necessary to use the over-lifting tension method to activate the cable and the instrument. After using this logging cable anti-sticking device, the over-lifting tension is significantly reduced compared to before. (3) The safety of logging operations can be improved. Since the risk of sticking and the over-lifting tension when sticking are reduced, this provides more engineering support for long-term stillness in the formation and escorts deeper sampling operations.

[0027] In a specific embodiment, the logging cable anti-sticking device was applied to logging operations in 12 wells, reducing the sticking rate by 32% on average and greatly improving the safety of the operation.

[0028] In a specific embodiment, the logging cable anti-sticking device was applied to a certain 25-1 oil field, and achieved good application results. The research results can directly serve the site, provide support for the deep formation exploration and development of Bohai Oilfield, and are the key technology for increasing reserves and production in Bohai Oilfield.

[0029] In a logging cable anti-sticking device provided by an embodiment of the utility model, the anti-sticking wire 2 is tightly wound around the outer surface of the cable body 1 along the spiral line direction, which can reduce the contact area between the cable and the formation during the contact between the cable and the formation, shorten the contact time between the cable and the formation, reduce the risk of cable sticking during deep formation pressure sampling operations, and adapt to the deep logging operation mode under the new situation.

[0030] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0031] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A logging cable anti-sticking device, comprising a cable body, characterized in that: The logging cable also includes: an anti-sticking wire, which is tightly wound around the outer surface of the cable body along the spiral line direction. The anti-sticking wire is a steel wire, and the ratio L of the steel wire length to the cable body length is 2.

2. The number of steel wires N is 3, and the spacing d between adjacent steel wires is 1.4 cm.

2. The logging cable anti-sticking device according to claim 1, characterized in that: The anti-sticking wire is spirally wound around the outer surface of the cable body in a clockwise direction.

3. The logging cable anti-sticking device according to claim 1, characterized in that: The diameter of the steel wire is 1 mm.

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