Apparatus and method for testing cementation capability of well cementation first and second interfaces under high-temperature high-pressure conditions

Abstract

The invention discloses an apparatus and a method for testing cementation capability of well cementation first and second interfaces under high-temperature high-pressure conditions. The apparatus is mainly composed of a kettle body, an outer pressure pump, an inner pressure pump, a heating belt, a surrounding pressure sleeve, an inner pressure pipe, a nitrogen source, a rotor flow meter, an observation conical flask, an outer pressure sensor, an outer galvanic couple, an inner pressure sensor, an inner galvanic couple, a gas-liquid discharge valve and a computer. The method comprises: (1) sleeving an imitated rock core with the surrounding pressure sleeve, putting in the kettle body and pouring a drilling fluid; (2) heating the kettle body, injecting a pressure P1 into the drilling fluid, and maintaining for 3 d to form an artificial mud cake; (3) pouring a cement slurry into an annular space formed by the inner pressure pipe and the imitated rock core, setting the temperature as a downhole temperature T1, pressurizing to a surrounding pressure P2 needed by an experiment, and maintaining for 3 d to form a cement sheath; and (4) pressurizing the interior of the inner pressure pipe to a pressure P3 needed by the experiment, and testing the cementation capability of the first and the second interfaces. The principle is reliable, the apparatus and the method are capable of accurately testing the cementation capability of the well cementation first and second interfaces under the high-temperature high-pressure conditions, and the evaluation result is relatively precise.

Description

technical field [0001] The invention relates to a device and method for testing the sealing ability of the first and second interface of cementing in the cementing process of oil and gas well engineering, which can simulate the formation of mud cake at the second interface and the sealing ability of the first and second interface of cementing under high temperature and high pressure conditions test. Background technique [0002] For oil and gas well cementing and completion projects, the cementing surface between the casing and the cement sheath is usually called the first cementing interface, and the cementing surface between the cement sheath and the formation is called the second cementing interface. It is an indisputable fact that the problem of the first and second interface of cementing is a complex engineering problem that has plagued the petroleum engineering field for a long time and needs to be solved urgently. Nowadays, most of the developed oilfields in eastern ...

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Problems solved by technology

Zhang Yuguang proposed the simulation experiment system and evaluation method of the cementing interface (Zhang Yuguang, Li Xinhong, Gao Yutang, etc. Effect of curing time and mud cake modifier on the cementing interface bond strength[J]. Oilfield Chemistry, 2010, 27( 2): 124-127), Cui Maorong proposed a high-temperature and high-pressure core filtration device (Cui Maorong, Ma Yong. A new method for evaluating the influence of drilling fluid filter cake on the cementation quality of the cementing interface [J]. Natural Gas Industry, 2006 , 26(12):92-93), Gu Jun proposed a simulation evaluation device for the sealing ability of the cementing interface (Gu Jun, Yang Weihua, Qin Wenzheng, etc. Research on the evaluation method of the sealing ability of the cementing interface [J ]. Acta Petroleum Sinica, 2008, 29 (3): 451-454), but there are many deficiencies in this device. The one is that the mud cake cannot be formed in the device, and the second is that the formed mud cake is only a "parallel" ideal. The structure does not conform to the actual "ring" structure. Third, it cannot truly simulate the well conditions under high temperature and high pressure conditions. Fourth, the device can only evaluate the second cementing interface, and cannot evaluate the sealing ability of the first cementing interface.

[0004] These research methods and evaluation devices are all trying to simulate the stress state of the cementing interface under downhole conditions, but there are also a lot of disadvantages

On the one hand, the mud cake at the cementing interface cannot be formed in the same device, and at the same time, the sealing ability of the cementing interface cannot be tested at the same time. On the other hand, these evaluation devices do not follow the actual combination structure for the first and second The evaluation of the interface, and based on the limitations of experimental equipment and conditions, seldom considers the quantitative evaluation of the sealing ability of the first and second interfaces of cementing under the conditions of high temperature, high pressure or changes in the two conditions.

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