Method for improving low-temperature rheological property of oil-based drilling fluid

Abstract

The invention discloses a method for improving the low-temperature rheological property of oil-based drilling fluid and relates to the technical field of petroleum and natural gas drilling. The method is characterized in that 0.4-1.2% of oil-soluble dispersing agent and / or 0.6-2.5% of pour point depressant are added on the basis of an existing oil-based drilling fluid formula. The method has the advantages that the viscosity and shearing force rising amplitude of the oil-based drilling fluid at low temperature can be lowered while various properties of existing oil-based drilling fluid are unaffected, the rheological property of the oil-based drilling fluid can be kept relatively stable, problems such as downhole complexity and pipeline blocking under low temperature due to excessively high equivalent circulating density are avoided, the dependence degree of the oil-based drilling fluid on heating facilities when the oil-based drilling fluid is used in cold regions is lowered at the same time, and energy conservation and emission reduction are achieved.

Description

technical field [0001] The invention relates to the technical field of oil and gas drilling, in particular to a method for improving the low-temperature rheology of oil-based drilling fluid. Background technique [0002] In special process wells such as complex formations or long horizontal sections, oil-based drilling fluids are often used, and the rheological properties of oil-based drilling fluids are greatly affected by temperature, especially when drilling in cold regions or in deep water conditions, oil-based drilling fluids Due to the influence of cold weather or the cooling effect of seawater, the viscosity and shear force will increase, and the equivalent circulation density will increase. What's more, the oil-based drilling fluid will not flow or the pipeline will be blocked, making it impossible to maintain the drilling operation. If the drilling safety density window is narrow, the increased circulating equivalent density will induce a series of complex accidents...

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Problems solved by technology

[0005] The purpose of the present invention is to provide a method for improving the low-temperature rheology of oil-based drilling fluid in view of the defects and deficiencies in the above-mentioned prior art. By adopting this method, the various properties of the existing oil-based drilling fluid can be improved. Reduce the viscosity and shear force increase of oil-based drilling fluid at low temperature, keep its rheological properties relatively stable, prevent downhole complexity caused by excessive equivalent circulation density, prevent pipeline blockage under low temperature conditions, and reduce the use of oil in cold regions. The dependence of base drilling fluid drilling on heating facilities has the effect of energy saving and emission reduction

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