Oil-based high-temperature and high-density drilling fluid for drilling wall reinforced rock gas reservoir

Abstract

The invention discloses an oil-based high-temperature and high-density drilling fluid for a drilling wall reinforced rock gas reservoir. The oil-based high-temperature and high-density drilling fluid comprises the following raw materials in parts by weight; 80 to 95 parts of an oil phase; 2-4 parts of a main emulsifier; 2-4 parts of an auxiliary emulsifier; 2-4 parts of a wetting agent; 0.5 to 3 parts of organic soil; 2-6 parts of a filtrate reducer; 0-3 parts of a flow pattern regulator; 2-8 parts of a while-drilling pressure-bearing plugging agent; 1-4 parts of a particle size variable composite blocking agent; 2 to 4 parts of lime; 3-5 parts of superfine calcium carbonate; 5 to 20 parts of 25% CaCl2 saline water; and API standard barite, wherein the weight is increased to 2.05-2.3 g/cm < 3 >. The while-drilling well wall reinforced shale gas reservoir oil-based high-temperature and high-density drilling fluid system is high in thermal stability under a high-temperature condition, the rheological property of the drilling fluid is easy to control, the while-drilling plugging performance is high, and the performance maintenance is simple.

Description

technical field [0001] The invention relates to the technical field of drilling fluid in oil and natural gas drilling engineering, in particular to an oil-based high-temperature and high-density drilling fluid for drilling wall strengthening rock gas reservoirs. Background technique [0002] my country is rich in shale gas resource reserves. The preliminary prediction of geological resource reserves is about 134×1012m3, and the technically recoverable reserves are as high as about 25×1012m3. It has broad development prospects. It is currently solving the shortage of oil and gas resources in my country and realizing oil and gas reserves and production. , an important measure to ensure national energy security. [0003] The Sichuan-Chongqing region has rich natural gas resources through early exploration, but its geological conditions are complex, characterized by deep burial and uneven lateral distribution of the reservoirs, and the development of micro-nano pores and fracture...

AI Technical Summary

Problems solved by technology

[0009] The purpose of the present invention is to provide a drilling wall strengthening type rock gas reservoir oil base high temperature high density drilling fluid, to solve the problem of how to improve the pressure bearing capacity of the shale reservoir by the method of drilling in the existing drilling process, so as to avoid Problems of borehole wall collapse and high-density oil-based drilling fluid-induced fracture loss

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