Fluid loss reducer for full oil-based drilling fluid and preparation method thereof

Abstract

The invention provides a filtrate loss reducer for full oil-based drilling fluid, and a preparation method of the filtrate loss reducer. The filtrate loss reducer comprises the following raw materials in parts by weight: 130-140 parts of an emulsion micelle compound and 20 parts of humic acid acetamide, wherein the emulsion micelle compound comprises the following raw materials in parts by weight: 60 parts of diesel oil, 10 parts of an emulsifying agent, and 60-70 parts of a macromolecular micelle compound. The filtrate loss reducer for full oil-based drilling fluid, which is provided by the invention, is simple in preparation technology, the performance of products is good, the rheological property and filtration reducing property of drilling fluids can be remained, the oil-gas layers can be effectively protected, the collapse of oil-gas layers is avoided, and the borehole diameter is prevented from enlarging.

Description

technical field [0001] The invention relates to a fluid loss reducer for full oil-based drilling fluid and a preparation method thereof, belonging to the field of petroleum exploration. Background technique [0002] In recent years, water-in-oil drilling fluid (dispersed phase content ≥ 10%) has been widely used, but there are still some deficiencies: ① Drilling fluid contains a large number of emulsified water droplets, with high plastic viscosity, which affects the ROP and causes reservoir Emulsification blockage; ②In order to maintain the stability of the emulsion, the amount of emulsifier is increased, which will cause the wettability of the rock surface to change from hydrophilic to oil-friendly, resulting in reservoir damage; ③The activity of water in the formation and the drilling fluid water The phase activity is difficult to achieve equilibrium, thus destabilizing the wellbore. Full oil-based drilling fluid contains a small amount of water (dispersibility content ≤...

AI Technical Summary

Problems solved by technology

[0002] In recent years, water-in-oil drilling fluid (dispersed phase content ≥ 10%) has been widely used, but there are still some deficiencies: ① Drilling fluid contains a large number of emulsified water droplets, with high plastic viscosity, which affects the ROP and causes reservoir Emulsification blockage; ②In order to maintain the stability of the emulsion, the amount of emulsifier is increased, which will cause the wettability of the rock surface to change from hydrophilic to oil-friendly, resulting in reservoir damage; ③The activity of water in the formation and the drilling fluid water Phase activity is difficult to achieve equilibrium, thus destabilizing the wellbore

Although the full oil base oil has the above advantages, its application and popularization are hindered due to the difficulty in controlling its fluid loss.

[0003] Shale gas wells in Weiyuan-Changning area in China have high density (>2.0g / cm 3 ), low temperature (70°C-90°C), and small pore throat radius (nano-micron level), etc., bring the following technical difficulties to high-density oil-based drilling fluids: difficult plugging and large fluid loss; ordinary bitumen Fluid loss additives have a high softening point, and are less effective at low temperatures; common fluid loss additives have too large a particle size, which does not match the size of shale pores, and cannot form a sealing plug

[0004] Therefore, it is an urgent problem to be solved in this field to provide a kind of fluid loss control agent which can solve the problem that the full oil-based fluid loss control is difficult

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