Device and method for simultaneous detection of displacement and sucking capillary force curves under oil reservoir conditions

Abstract

The invention relates to a device and a method for simultaneous detection of displacement and sucking capillary force curves under oil reservoir conditions. The device comprises a triaxial stress rockcore holder, wherein a wet phase semi-permeable separator and a non-wetting phase semi-permeable separator are respectively placed at both ends of a rock core, an annular pressure and axial pressuremechanical pump and a back pressure mechanical pump are used to pressurize and simulate formation pressure, a thermostat simulates formation temperature, a non-wetting phase fluid piston container, awet phase fluid piston container and a constant speed constant pressure micro pump control a displacement and suction process, a pressure flow rate sensor group, a pressure gauge, a metering tube anda computer collect pressure and liquid volume data and process and calculate the displacement and sucking capillary force curves; the method continuously measures the displacement and sucking capillary force curves of different wettable rocks in one time and scans the displacement and sucking capillary force curves by simulating true oil reservoir temperature pressure and fluid conditions, makes up for the shortcomings of conventional methods, solves the defect that a common instrument can only measure displacement capillary force curves, and solves the problem of continuous accurate measurement of underground real displacement and sucking capillary force curves.

Description

technical field [0001] The invention belongs to the field of evaluation of special physical properties of reservoir rocks, and in particular relates to a device and method for joint measurement of displacement and suction capillary force curves under oil reservoir conditions. Background technique [0002] Due to the small pores of low-permeability and tight oil and gas reservoirs, the capillary force curve is an important basic data for the development and design of such reservoirs, especially for the calculation of oil and gas reserves in the transition zone of hundreds of meters. Commonly used methods for measuring capillary force curves include semi-permeable diaphragm method, mercury intrusion method and centrifugation method. The parameters used to obtain the subsurface capillary force curve obtained through conversion and calculation of mercury injection capillary force cannot be accurately measured, resulting in a large deviation between the converted subsurface capil...

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Problems solved by technology

The parameters used to obtain the subsurface capillary force curve obtained through conversion and calculation of mercury injection capillary force cannot be accurately measured, resulting in a large deviation between the converted subsurface capillary force curve and the actual; centrifugation method is difficult to simulate the characteristics of high temperature and high pressure reservoir conditions; use The semi-permeable diaphragm method can more realistically simulate the temperature and pressure conditions of the reservoir. Some institutions have developed a high-temperature and high-pressure capillary force curve measuring instrument using the semi-permeable diaphragm method

The current existing methods are to directly or indirectly measure the displacement capillary force curve, but in the different processes of reservoir formation and development, the displacement and sucking process between the wetting phase and the non-wetting phase fluid are very different, and the displacement The replacement and suction capillary force curves have different influences on the dynamic simulation and planning of oil and gas field development and cannot be mixed

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