An organic salt drilling fluid

Abstract

The invention discloses organic salt drilling fluid. The organic salt drilling fluid is prepared from 1%-4% of bentonite, 0.3%-0.5% of sodium carbonate, 0.5%-1% of sodium hydroxide, 0.3%-1% of xanthan gum, 2%-8% of a filtrate loss reducer, 2%-5% of a nanometer blocking agent, 1%-4% of a blocking agent, 0.5%-4% of a lubricating agent, 40%-60% of organic salt and 25%-250% of an inert weighting agent, wherein the nanometer blocking agent is prepared by copolymerizing methacrylic acid carbomethoxy cage-like oligomeric silsesquioxane, N-isopropylacrylamide and acrylamide, and the lubricating agent is prepared by compounding castor oil polyoxyethylene ether, polyethylene glycol and polyvinyl pyrrolidone. The organic salt drilling fluid has the very good heat stability, the low filtration loss and the high blocking performance and lubricating performance and is especially suitable for shale gas well development.

Description

Technical field

[0001] The invention relates to the field of petroleum and natural gas, in particular to an organic salt drilling fluid. Background technique

[0002] With the development of the domestic and international petroleum industry and the increasing demand for petroleum, the development and utilization of shale gas has gradually increased. At present, the exploitation of shale gas mainly uses oil-based drilling fluid. Oil-based drilling fluid has strong plugging properties and good lubricity, and is widely used in the exploration and development of shale gas wells. However, oil-based drilling fluids have problems such as high cost and pollution to the formation and the environment. If ordinary water-based drilling fluids are used, due to the well-developed shale formation fractures and strong water sensitivity, contact with water-based drilling fluids can easily cause leakage and collapse. In addition, due to the long horizontal well section in shale gas drilling, the ...

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