Drilling fluid for improving formation pressure bearing capacity and its preparation method and application

Abstract

The invention relates to the field of drilling mud in the petroleum industry, and discloses a drilling fluid for improving the pressure bearing capacity of formations, a preparation method and application thereof. The drilling fluid comprises water, bentonite, low-viscosity polyanionic cellulose, lignite resin, anti-high temperature and anti-salt fluid loss reducer, silanol inhibitor, inorganic micro-nano rigid particles and emulsified asphalt; based on 100 parts by weight of water , the bentonite is 2-9 parts by weight, the low-viscosity polyanionic cellulose is 0.1-1 parts by weight, the lignite resin is 1-5 parts by weight, and the high-temperature and salt-resistant fluid loss reducer is 0.1-1 parts by weight. 2 parts by weight, the silanol inhibitor is 0.1-2 parts by weight, the inorganic micro-nano rigid particle is 0.5-5 parts by weight, and the emulsified asphalt is 1-10 parts by weight. The drilling fluid has high formation pressure bearing capacity, and has excellent plugging effect when used in weak formations or deep formations.

Description

technical field [0001] The invention relates to the field of drilling mud in the petroleum industry, in particular to a drilling fluid for improving the pressure bearing capacity of formations, a preparation method and application thereof. Background technique [0002] In the process of drilling deep formations, under the action of continuous high temperature, conventional drilling fluid thickens seriously, and the contradiction between rheology and fluid loss wall building is prominent, and it is easy to be polluted by salt, gypsum and calcium intrusion, which leads to the deterioration of drilling fluid performance , Maintenance processing is complex, and even lead to a series of downhole complex situations. Under normal circumstances, there are a large number of fractures in the collapsed formation. When drilling into the formation, the drilling fluid will quickly enter the formation along these fractures. At the same time, the mud shale will expand and disperse when it e...

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Problems solved by technology

[0003] The purpose of the present invention is to overcome the existing problems in the prior art in the drilling process of weak formations or deep formations, such as block dropping, sticking and sticking, and lost circulation during drilling due to the low pressure bearing capacity of the formations, and provide a A drilling fluid providing high formation pressure bearing capacity and its preparation method and application. The drilling fluid has high formation pressure bearing capacity and has excellent plugging effect when used in weak formations or deep formations

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