Reservoir capillary pressure curve determinator under high temperature and pressure

Abstract

The invention provides a reservoir capillary pressure curve determinator under a high temperature and a pressure. The determinator comprises a ring pressure system, an injection system, a core clamping system, a semi-permeable baffle plate, a back pressure system, a measuring system, a data automatically collecting and processing system, and a thermostat which are connected through pipelines. A semi-permeable baffle plate method is adopted to measure capillary pressure curves under a stratum condition, and the basic rationale is that a principle of balance between an impressed pressure and the capillary pressure is used to measure the capillary pressure curves under the high temperature and the pressure. Core saturated wetting phase fluid displaces a wetting phase with a nonwetting phase under a certain displacement pressure. When the impressed pressure overcomes the capillary pressure of a certain capillary in the core, the wetting phase fluid in the capillary is discharged gradually, and the wetting phase fluid saturation in the core is reduced. Pressure is increased stepwise, accumulated discharged quantity of the wetting phase fluid when the wetting phase fluid is no longer discharged and an injection pressure are measured, and the capillary pressure curves can be solved.

Description

Technical field: [0001] The invention relates to an oil reservoir capillary pressure curve measuring device under high temperature and high pressure conditions, which belongs to the field of experimental equipment for oil exploitation. Background technique: [0002] The capillary pressure curve is the most basic and important data for reservoir development dynamic calculation and program formulation, and is an essential data for oilfield development. At present, the capillary pressure curve can only be measured under ground conditions, and the commonly used methods include semi-permeable diaphragm method, mercury injection method and centrifugation method. The formation capillary pressure under high temperature and high pressure can only be calculated according to the oil-water, oil-gas interfacial tension and rock wetting angle under the formation conditions, but the interfacial tension and rock wetting angle under the formation conditions cannot be accurately measured at p...

AI Technical Summary

Problems solved by technology

The formation capillary pressure under high temperature and high pressure can only be calculated according to the oil-water, oil-gas interfacial tension and rock wetting angle under the formation conditions, but the interfacial tension and rock wetting angle under the formation conditions cannot be accurately measured at present, which makes the calculation difficult. big error

Therefore, it is very necessary to study the method of measuring the capillary pressure curve of the reservoir under the condition of high temperature and high pressure and the development of related equipment. At present, there are no reports of similar equipment at home and abroad.

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