Well cementation two-interface cementing quality evaluation device and method

Abstract

The invention relates to a well cementation two-interface cementing quality evaluation device and method. The device consists of a cylindrical kettle body 1, a core 4, a fluid pressure pump 11, a pressure sensor 12 and the like. The kettle body is provided with an upper seal cover 2 and a lower seal cover 3 which are detachable, the upper seal cover is provided with a liquid and gas inlet 6, a pressure relief valve 9 and the pressure sensor 12, and the lower seal cover is provided with liquid and gas outlets 7; and the core 4 is arranged in the kettle body, a filter cake is arranged on the surface of the core, and a cement ring is arranged in an annular space between the core and the kettle body. The method includes the steps of vacuumizing the core with the filter cake to enable the coreto be saturated in resin; placing the core in the kettle body, adding well cementation cement slurry, curing for a certain period of time, and forming the cement ring between the core and the inner wall of the kettle body; injecting fluid into the kettle body; and recording the rupture pressure generated when the two-interface filter cake is broken to form a fluid moving channel, and obtaining thetwo-interface cementing coefficient. The well cementation two-interface cementing quality evaluation device and method can effectively avoid fluid seepage from the core, truly reflect the well cementation two-interface cementing quality and have broad market prospects.

Description

technical field [0001] The invention relates to a cementing quality evaluation device and method for cementing two interfaces in the well cementing process in the field of exploration and development of oil and gas wells. 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. The cement sheath body and the first and second interface of cementing together constitute the cementing cement sheath sealing system. The quality of the cementing and sealing system is directly related to the productivity and life of oil and gas wells, and directly related to the development benefits of oil fields. If the cement sheath reduces or even loses the effect of interlayer isolation, it will induce formation fluid channeling and pressure in t...

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Problems solved by technology

For example, some scholars use a press to test the shear pressure required for complete slippage between the core and the cement sheath in the presence of a filter cake (Cui Maorong, Ma Yong, CuiMaorong, et al. A new method for evaluating the influence of drilling fluid filter cake on the cementing quality of the cementing interface [J]. Natural Gas Industry, 2006, 26 (12): 92-93), but the actual situation is that the rock formation and the cement sheath will hardly slip out of the downhole, and the isolation ability of the two interfaces to the formation fluid cannot be evaluated; there are also Some scholars regard the filter cake as a permeable substance, and use liquid to pass through the sample at one end of the core to test the seepage flow rate, so as to evaluate the cementation quality of the second interface (Gu Jun, Yang Weihua, Qin Wenzheng, et al. [J]. Acta Petroleum Sinica, 2008, 29(3)), but this method does not consider the seepage of liquid from the core, and also cannot reflect the real cementing quality of the cementing interface.

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