Tight sandstone gas reservoir fracturing fluid damage experimental evaluation method

Abstract

The invention belongs to the field of oil-gas field development and relates to an experimental evaluation method for fracturing fluid damage in an unconventional tight sandstone oil-gas exploration and development process. The method includes: subjecting fracturing fluid to high-pressure instant reverse injection into a rock core, and simulating flow invasion damages of fracturing fluid in cracks in a continuous extension process after a stratum is fractured by the fracturing fluid; adopting a high-speed centrifuge to set up original water saturation of a reservoir; under the condition of the original water saturation of the reservoir, adopting nitrogen for testing permeability before and after injection of the fracturing fluid into the rock core, and judging fracturing fluid damage degrees according to gas log permeability change rate. By complete simulation of a fracturing fluid injection mode in a fracturing process, adoption of nitrogen for testing permeability accords with seepage characteristics of the tight sandstone gas reservoir, and defects of high experimental displacement pressure, long displacement time, large experimental data errors and the like are avoided.

Description

technical field [0001] The invention relates to an evaluation experiment method for fracturing fluid damage during unconventional tight sandstone oil and gas exploration and development, and belongs to the field of oil and gas field development. Background technique [0002] Tight sandstone gas has a wide distribution range and huge reserves in the world. The technology for its exploration and development is closely related to the technology used for conventional oil and gas resources. Most of the technologies used for the exploration and development of conventional oil and gas resources are also applicable to Tight sandstone gas system, so tight sandstone gas is often called "unconventional conventional energy". Among them, in 2010, the total gas production of large tight sandstone fields in my country was 222.5×10 8 m 3 , accounting for 23.5% of the national gas production that year. It can be seen that the total reserves and annual production of large tight sandstone f...

AI Technical Summary

Problems solved by technology

However, the current industry-standard evaluation methods cannot fully meet the development needs of tight sandstone gas, and the formation of a fracturing fluid damage evaluation method for tight reservoirs is of great significance for the protection of tight sandstone gas reservoirs and economic development

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