Oil/gas well cement sheath sealing integrity testing device and method for carrying out evaluation through device

Abstract

The invention relates to an oil / gas well cement sheath sealing integrity testing device. The testing device comprises a pressure kettle and a simulation wellbore located in the pressure kettle. The testing device further comprises a pressure control system, a temperature control system, a fluid channeling detection system, a strain measuring system and a mud cake simulation system. The simulation wellbore comprises a casing pipe and a core located on the periphery of the casing pipe. An annular gap is formed between the sleeve and the core, and a cement sheath is formed in the annular gap. The upper ends and the lower ends of the casing pipe and the core are provided with an upper end cover and a lower end cover respectively. The temperature borne by the cement sheath under different downhole working conditions and complex loads from the casing pipe and a stratum can be truly simulated, and the process range covers well cementation at the oil / gas well drilling and completion stage and pressure tests, producing tests, circulating injection production, fracturing and other improvement working conditions in the production process. The influence rule of the cement sheath sealing integrity can be evaluated by changing the thickness of the cement sheath, the character of mud cakes, the maintenance temperature and other factors.

Description

Technical field

[0001] The invention belongs to the field of oil and gas resource development, and specifically relates to a device and an evaluation method that can simulate the casing and stratum complex loads borne by a cement ring under downhole working conditions, and test the sealing integrity of the cement ring. Background technique

[0002] In all stages of the life cycle of an oil and gas well, the control of the fluid in the wellbore and formation is the primary task. If the fluid flows uncontrollably, the oil and gas wells will not have physical and functional integrity, which may lead to serious and even catastrophic consequences. As an important part of the wellbore of oil and gas wells, the main function of the cement ring is to prevent the flow of formation fluids in the process of drilling, production and reconstruction, and to effectively fix and support the casing. In recent years, with the in-depth development of the exploration and development process, most o...

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