Strong-plugging hydrophobic high-performance water-based drilling fluid

Abstract

The invention provides a strong-plugging hydrophobic high-performance water-based drilling fluid. The strong-plugging hydrophobic high-performance water-based drilling fluid comprises bentonite slurry, sodium hydroxide, a polymer coating inhibitor, a filtrate reducer, an anti-collapse agent, a lubricant, a plugging agent, an activity regulator and a tackifying and shear strength improving agent. According to the strong-plugging hydrophobic high-performance water-based drilling fluid of the invention, the polymer coating inhibitor, the filtrate reducer, the anti-sloughing agent, the lubricant,the blocking agent and the tackifying and shear strength improving agent are used as core treating agents, so that the well wall stability, the inhibition capability, the lithology carrying capabilityand the lubricating anti-sticking performance of the obtained water-based drilling fluid completely meet the requirements of a tight gas exploratory well and a development well in a Linxing-Shenfu block; the plugging of micro-nano hole seams is realized; the large-amplitude hydration expansion of shale is avoided; a good lubricating effect is achieved; the underground pressure supporting condition is effectively reduced; the purposes of improving the mechanical drilling speed, reducing the underground accident rate and saving the cost are achieved; the environment-friendly requirement can bemet; the product is a non-toxic pollution-free product; the cost of the product is low; and the economic requirement is met.

Description

technical field [0001] The invention belongs to the technical field of petroleum drilling engineering, and in particular relates to a strong plugging and hydrophobic type high-performance water-based drilling fluid. Background technique [0002] The Linxing-Shenfu tight gas block located on the eastern edge of the Ordos Basin is currently in the initial stage of exploration and development. With the continuous increase of drilling operations, the geological conditions of the formation have been basically understood, and the single well is prone to leakage, collapse and anomalies. The formation has a certain understanding. During the drilling process, the drilling fluid faces many technical difficulties, such as: wellbore stability, lost circulation, wellbore purification (drilling fluid carrying rock), lubrication and anti-seizing, high cost, etc., especially in the upper Quaternary slate of this block. Vicious leakage in the formation, Yanchang Formation to Zhifang Formati...

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Problems solved by technology

[0004] The brine drilling fluid used in the early stage of this block has poor inhibition and cannot effectively seal the micro-cracks and pores existing in the shale formation. At the same time, the ability to lubricate and prevent sticking is insufficient, resulting in frequent occurrence of bit bumps, well wall dropouts, etc. during drilling operations. Complicated downhole conditions such as accumulation of cuttings bed, sticking and severe back pressure have affected the efficient completion of logging and cementing operations. The performance of existing drilling fluids cannot meet the actual requirements of downhole formations, which seriously restricts the compactness of this block. In the process of gas exploration and development, the difficulty of drilling fluid to meet the requirements has become an important obstacle to the comprehensive, efficient, economical and safe development of tight gas in the Linxing-Shenfu block

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