CN209892182U - Simple device for measuring cementing strength of abandoned well cement plug and casing interface - Google Patents

Abstract

A simple device for measuring the cementing strength of the interface of a cement plug and a casing of a abandoned well comprises a pressure head 1, an upper guide pipe 2, a sample pipe 3, a lower guide pipe 4 and a base 5. The method is characterized in that: the upper guide pipe and the lower guide pipe are connected with the sample tube by threads, so that stable clamping in the experimental process is kept. The sample tube connected with the upper guide tube and the lower guide tube is arranged on a base, and the base is fixedly coupled with a centering pin of a loading equipment press. The pressure head is connected with the upper guide pipe, and the coupling structure ensures that the load transmitted by the pressure head vertically acts on the end face of the sample tube under the condition that the cement end face is not flat. During the experiment, the load vertically acts on the pressure head. The novel stainless steel anti-corrosion device is completely made of stainless steel materials, meets the anti-corrosion requirement, and can be repeatedly used under the condition that the device is not damaged by physical damage; the device is quick and convenient to assemble, simple and easy to operate and convenient to adjust; the pressure head, the upper guide pipe, the lower guide pipe and the base can be matched with the requirement of the sample tube to change the size, and all parts of the device are convenient to disassemble and assemble, so that the device has universality.

Description

Simple device for measuring cementing strength of abandoned well cement plug and casing interface

Technical Field

The utility model discloses a log abandon well cement stopper and simple and easy device of sleeve pipe interface cementation intensity.

Background

China is rich in marine oil and gas resources, and currently China has obtained great results in exploration in regions such as the south sea, the Bohai sea and the like, but the operation cost of a marine exploration well single well can reach hundreds of millions of RMB, and in fact, the operation cost of a marine development well is higher, and a high economic threshold becomes a key factor for limiting the development of marine oil and gas resources. Offshore exploration and development integration strategy is one of the effective ways to alleviate this problem. The technology of converting offshore exploration wells into development wells is an important part of the integration of deep water exploration and development. The exploratory well production casing pipe with the found reserves is connected back to the wellhead, and is directly converted into the exploitation well production by means of the existing and later-equipped production facilities, the exploratory well is not required to be abandoned and a new exploitation well is drilled again, the exploitation period can be shortened by more than 1 year, and the operation period and the exploitation cost are greatly reduced.

After geological data required by oil and gas development is obtained, a cement plug is punched in the exploratory well to seal the bottom layer of the open hole. The operation of abandoning the well should make the well inside and outside have no passageway that stratum fluid flees upward, stratum fluid does not flee to the mud face of seabed, the risk of polluting the marine environment. The annular pressure can experience a plurality of shaft states in the process of transferring the exploratory well to the exploitation well, and the annular pressure comprises an exploratory well drilling stage, a long-term idle stage after abandoning the exploratory well, a re-entry stage of transferring the exploitation well completion and a production stage, wherein the working conditions and temperature and pressure environments of the shaft in each stage are different, and the annular pressure changes greatly.

Therefore, by researching the well abandoning cement plug, the well abandoning safety and feasibility evaluation of well abandoning and exploratory well-to-development can be obtained. The domestic research on the failure mechanism of the cement plug of the abandoned well mostly comprises the steps of placing a cement plug sample in a simulated formation corrosion environment for maintenance through a corrosion test, and testing the change of the porosity and the permeability of the cement plug sample in different periods to explain. While we believe that these studies of the cement plug failure mechanism neglect the effect of bond strength changes between the cement plug and the casing on annular pressurization. More specifically, we believe that the impact of the corrosive environment on the failure of the cement plug should be evaluated in two dimensions, namely the impact of the corrosive environment on the porosity and permeability of the cement plug and the impact of the corrosive environment on the bond strength between the cement plug and the casing.

The test of the cementing strength of the cement plug and the casing needs to load a load on an experimental cement plug sample to obtain the shear strength of the damaged casing and the cement plug. The clamping stability of the sample during the experiment is a prominent problem, namely, the applied load can not be kept to be vertically applied to the axial direction of the sample during the loading process. Therefore, the cementing strength between the cement plug sample and the casing pipe can not be damaged under the condition that the applied load does not reach the value, the sample is firstly subjected to shearing damage under the load, and the experimental purpose cannot be achieved.

Disclosure of Invention

To the above problem, the utility model aims at providing a survey abandon well cement stopper and sleeve pipe interface cementation intensity's simple and easy device. The device can fix the sample and ensure that the load vertically acts on the axis of the sample during the loading process.

In order to achieve the purpose, the utility model adopts the following technical proposal: the utility model provides a log abandoned well cement stopper and simple and easy device of sleeve pipe interface cementation intensity which characterized in that: the device comprises an upper guide pipe, a sample tube, a lower guide pipe, a pressure head and a base.

The equipment connection sequence is that firstly, a cement sample is poured into the sample tube, then the upper guide tube and the lower guide tube are respectively connected with the upper part and the lower part of the sample tube by screw threads, finally, the pressure head is arranged on the upper guide tube, and the base is arranged below the lower guide tube. During the experiment, the load is vertically loaded on the upper part of the pressure head.

The utility model discloses owing to take above technical scheme, it has following advantage:

1. the sample is stabilized, the vertical loading in the axial direction of the sample is ensured, and the cementing shear force between the sample and the steel pipe is measured.

2. The experiment takes cement plug failure cause ignored by others, namely cementation failure between the cement plug and the casing into consideration to carry out a comparison test, and designs a special clamping device optimization experiment, thereby having important significance for the research of cement plug corrosion failure mechanism.

Drawings

FIG. 1 is a combination drawing of the components of the apparatus, i.e., the apparatus; FIG. 2 is a schematic view of the ram; FIG. 3 is a schematic view of an upper duct; FIG. 4 is a schematic view of a sample tube; FIG. 5 is a schematic view of the lower conduit; fig. 6 is a schematic view of a base.

Detailed Description

The present invention will be described in detail with reference to the accompanying drawings and examples.

The simple and easy device of log abandonment well cement stopper and sleeve pipe interface cementation intensity includes: 1. a pressure head 2, an upper guide pipe 3, a sample tube 4, a lower guide pipe 5 and a base.

The method is characterized in that:

(1) the pressure head 1, the upper guide pipe 2, the sample tube 3, the lower guide pipe 4 and the base 5 are all made of stainless steel materials, the corrosion resistance degree is high, and the parts of the device can be used repeatedly.

(2) The pressure head 1 comprises two cylindrical structures, wherein the upper part of the pressure head is a cylinder with the diameter of 50mm and the height of 15mm, and the lower part of the pressure head is a cylinder with the diameter of 18mm and the height of 20 mm. When in use, an inverted T-shaped structure is formed, and the lower cylindrical ground is directly contacted with the interface of the sample tube to transfer load.

(3) The upper guide pipe 2 is a circular pipe with a reducing structure. The upper portion is that the internal diameter is 19mm, and the external diameter is 30mm, highly is 10 mm's ring column structure, and the lower part is that the internal diameter is 25mm, and the external diameter is 30mm, highly is 10 mm's ring column structure, and lower part ring column has highly is 10 mm's internal thread structure simultaneously. The inner diameter of the upper circular column is 19mm, which is slightly larger than the diameter of the lower circular column of the pressure head 1 by 18mm, so that the pressure head 1 and the upper guide pipe 2 form a coupling structure.

(4) The sample tube 3 is a cylinder with a diameter of 25mm, and has an external thread structure with a length of 15mm at the top thereof for connecting with the lower part of the upper guide tube 2. The lower part of the pipe body is provided with an external thread structure with the length of 15mm and is used for being connected with the upper part of the lower guide pipe 4.

(5) The lower guide pipe 4 is a circular pipe with a reducing structure. The upper part is a circular column structure with the inner diameter of 25mm, the outer diameter of 30mm and the height of 10mm, and an external thread structure with the length of 10mm is arranged in the circular column structure and is connected with the sample tube 3. The lower part is a circular column structure with the inner diameter of 21mm, the outer diameter of 30mm and the height of 15 mm.

(6) The base 5 comprises two cylindrical structures, the upper part of which is a cylinder with the diameter of 21mm and the height of 5 mm. The lower part is a cylinder with the diameter of 50mm and the height of 20mm, and the lower part comprises a clamping groove with a central hollow structure. And the hollow structure is a cylinder with the inner diameter of 6.2mm and the height of 15mm and is used for being coupled with a centering pin of a loading equipment press to fix a sample.

(7) The pressure head 1, the upper guide pipe 2, the lower guide pipe 4 and the base 5 can be matched with the requirement of the sample tube 3 to change the size, and all parts of the device are convenient to disassemble and assemble, so that the device has good universality.

The utility model discloses a use does:

1) and (3) pouring the sample cement into the sample tube 3, and maintaining under the experimental conditions.

2) The upper guide pipe 2 and the lower guide pipe 4 are connected with the sample tube 3 by screw threads.

3) The sample tube 3 connected with the upper guide tube 2 and the lower guide tube 4 is arranged on a base 5, and the base 5 is fixedly coupled with a centering pin of a loading equipment press.

4) A ram 1 is coupled to an upper conduit 2.

5) During the experiment, load acts on pressure head 1 perpendicularly, records axial force and pressure head 1 displacement data.

6) And calculating to obtain the interface cementation strength by combining the side area of the inner wall of the sample tube 3 and the axial force data recorded in the previous step.

Claims (1)

1. A simple device for measuring the cementing strength of the interface of a cement plug and a casing of a abandoned well comprises a pressure head, an upper guide pipe, a sample tube, a lower guide pipe and a base; the method is characterized in that: cement samples are poured into the sample tube, an upper guide tube and a lower guide tube are respectively connected to the upper part and the lower part of the sample tube by threads, a pressure head is arranged on the upper guide tube, a base is arranged below the lower guide tube, and a load is vertically loaded on the upper part of the pressure head; the upper part of the guide pipe is designed into a diameter-variable circular pipe, the upper part of the guide pipe is of a circular ring column structure with the inner diameter of 19mm, the outer diameter of 30mm and the height of 10mm, the lower part of the guide pipe is of a circular ring column structure with the inner diameter of 25mm, the outer diameter of 30mm and the height of 10mm, and meanwhile, the circular ring column at the lower part of the guide pipe is of an internal thread structure with the height of 10 mm; wherein the lower part pipe is the reducing structure pipe, and its inside has the external screw thread structure that is 10mm long to be used for being connected with sample cell 3, and its lower part is the internal diameter simultaneously and is 21mm, and the external diameter is 30mm, and the height is the ring column structure of 15mm, and the lower part pipe forms "T" type structure after being connected with the sample cell.

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