Static test method for oil and gas well working fluid reservoir protection effect

Abstract

The invention discloses a static testing method for the working fluid reservoir protection effect of an oil gas well. The method comprises the steps that (a) working fluid is prepared; (b) simulated formation water is prepared and loaded into a testing device; (c) a simulated downhole is saturated with water; (d) displacement fluid is injected, displacement pressure is set to be P0, and displacement flow is Q0 when testing is stable; (e) the displacement fluid is drained, and the working fluid is injected; (f) the simulated downhole is preheated to the reservoir temperature; (g) the working fluid is pressurized, and timing is performed; (h) the filtration conditions of the working fluid are determined till the set time is up; (i) the working fluid is drained, displacement fluid is injected, and the conditions of flow Qi for changing along with displacement time are determined; (j) a recovery value Ki is calculated, wherein the displacement mode of the fluid in the step (d) and the displacement mode of the fluid in the step (i) are reverse displacement, and the displacement mode of the fluid in the step (e) is forward displacement. According to the static testing method, study of simulated experiments of the working fluid reservoir protection effect of the oil gas well is achieved under the condition of completely simulating the characteristics of the oil gas well and standing for well killing, and the risk that as the working fluid damages the immediate vicinity of a wellbore, capacity loss is caused is reduced or avoided.

Description

technical field [0001] The invention belongs to the technical field of experimental research and testing in the process of petroleum exploration and development, and specifically refers to a static testing method for the protection effect of oil and gas well working fluid reservoirs. Background technique [0002] Oil and gas well working fluid refers to the working fluid used in drilling, well completion, workover and other operations. In addition to meeting the safety, environmental protection and engineering requirements, the working fluid also needs to be used in reservoir sections. Meet reservoir protection requirements. Before the working fluid is applied to the field, an indoor simulation study is usually carried out, and it can only be applied to the field after meeting the requirements. For indoor research on the reservoir protection effect of oil and gas well working fluid, artificial or natural columnar cores (diameter 2.54cm, length about 10cm) are usually select...

AI Technical Summary

Problems solved by technology

For indoor research on the reservoir protection effect of oil and gas well working fluid, artificial or natural columnar cores (diameter 2.54cm, length about 10cm) are usually selected, and the work is carried out in the well-entry fluid damage evaluation device or dynamic damage evaluation system according to the petroleum industry standard experimental method. The simulated experimental research on the reservoir protection effect of the working fluid basically reflects the influence of the working fluid on the porosity and permeability of the reservoir, but it cannot represent the damage of the working fluid to the overall near-wellbore zone when there are screens or gravel packs. Therefore, the current The method cannot measure the reservoir protection effect of the working fluid under the condition of completely simulating the characteristics of the oil and gas well, which will increase the risk of the working fluid damaging the near-wellbore zone and causing a decline in productivity

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