Clay-free high temperature resistance reservoir drilling fluid and preparation method thereof

Abstract

The invention relates to clay-free high temperature resistance reservoir drilling fluid and a preparation method of the fluid. The reservoir drilling fluid comprises 100 parts by weight of fresh water, 150-220 parts by weight of potassium formate, 0.2-0.25 parts by weight of pH (potential of hydrogen) regulator, 2-3 parts by weight of high temperature resistance fluid loss agent, 0.4-0.8 parts by weight of high temperature resistance shear strength improving agent, 5-8 parts by weight of calcium carbonate, and 0-200 parts by weight of manganese ore powder. The method comprises the steps of dissolving the parts by weight of potassium formate in the fresh water, and adding the parts by weight of pH regulator, high temperature resistance fluid loss agent, high temperature resistance shear strength improving agent, calcium carbonate and manganese ore powder for agitation. The reservoir drilling fluid can meet higher density requirements, has good stability, can keep stable when used at high temperature (such as 150-160 DEG C), has good reservoir protection performance, sedimentation stability and highly-deviated well cutting carrying capacity and can meet drilling requirements of a horizontal well.

Description

technical field [0001] The present application relates to but not limited to a reservoir drilling fluid and a preparation method thereof, specifically to but not limited to a soil-free and high temperature resistant reservoir drilling fluid and a preparation method thereof. Background technique [0002] Reservoir drilling fluid is a working fluid used in reservoir sections that takes into account both the functions of drilling fluid and well completion fluid. Reservoir drilling fluid usually does not contain solid phase, and sometimes acid-soluble solid phase is added to adjust density or prevent leakage, but it should not contain bentonite or barite that is easy to plug the reservoir. At present, the density of domestic reservoir drilling fluid systems without soil phase and barite in the strict sense is generally 1.60g / cm 3 Within, and the temperature resistance is generally within 120 ℃. When faced with higher density requirements, it is often necessary to add barite fo...

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Problems solved by technology

In addition, when the bottom hole temperature is low, the performance of the reservoir drilling fluid can be maintained through the polymer, but at a high temperature exceeding 150°C, conventional polymers will degrade, resulting in deterioration of the performance of the reservoir drilling fluid system. Therefore, the solid-free reservoir drilling fluid suitable for high temperature has always been a difficult point of public relations in the industry

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