A drilling fluid cleaning slurry for wellbore purification and its preparation and use method

Abstract

The invention discloses a drilling fluid cleaning slurry for wellbore purification and its preparation and use method. The cleaning slurry includes a pre-sweeping slurry and a post-sweeping slurry, wherein the pre-sweeping slurry is composed of the following components by mass percentage : 0.1%~1.0% polymer viscosity enhancer, 0.2%~1.5% plugging agent, 1.0%~15.0% coarse particle plugging agent, 0.1%~1.5% drilling fluid lubricant, clean water to make up the balance , wherein the post-cleaning slurry is composed of the following components by mass percentage: 0.1% to 1.0% of polymer viscosity raising agent and / or 1.0% to 8.0% of weighting agent, 2.0% to 15.0% of coarse particle plugging agent, Drilling fluid makes up the balance.

Description

technical field

[0001] The invention belongs to the technical field of drilling fluid formula and treatment technology, and in particular relates to a drilling fluid cleaning slurry for wellbore purification and a preparation and use method thereof. Background technique

[0002] The Ecuador Basin is located in the Amazon tropical rainforest in the east of the country. It has rich oil reservoirs, complex geological structure, and high environmental protection requirements, which have brought many problems to drilling operations. This block is mainly developed by directional wells and horizontal wells. Mudstone, argillaceous sandstone, mixed with gravel. The characteristics of the upper formation are relatively new, the mudstone is soft, and the slurry is serious. In particular, the mudstone cuttings may form sticky mud, or cling to the well wall, or thicken the virtual mud cake, or cause mud balling of the drilling tool, resulting in difficulty in tripping , the mud blocks b...

Images