Slurry for protecting oil and gas reservoir

Abstract

The invention provides slurry for protecting an oil and gas reservoir, and belongs to the field of oil field drilling engineering. The problem that existing common slurry cannot meet complex conditions of oil and gas reservoir protection is solved. The slurry for protecting the oil and gas reservoir is prepared from, by weight, 25-40 parts of bentonite, 3 parts of xanthan gum, 0.1-0.3 part of potassium hydroxide, 2 parts of hydroxyethyl cellulose, 2 parts of sulfonated-pheno-formoldehyde resin, 1 part of ammonio hydrolysis polyacrylonitrile, 2-3 parts of potassium tannate, 40-50 parts of potassium formate, 10-30 parts of sodium formate, 1-30 parts of active barite, 1 part of sulfonated lignite, 5 parts of hydroxypropyl starch, 4 parts of white asphalt, 2.5 parts of graphite, 2-3 parts of calcium carbonate powder and 1000 parts of water. The slurry for protecting the oil and gas reservoir is high in compatibility with oil and gas reservoir rock and fluid, ensures the original balance of the oil and gas reservoir to the greatest extent, protects the oil and gas reservoir to the maximum degree, and is more beneficial to development of all kinds of work of oil testing or production departments in the future.

Description

technical field [0001] The invention belongs to the field of oil field drilling engineering, and in particular relates to a mud used for protecting oil and gas layers in oil drilling and production. Background technique [0002] The purpose of drilling is to deliver a non-damage or low-damage oil and gas well to the oil testing or production department. The damage to oil and gas layers during drilling not only affects the discovery of oil and gas layers and the production of oil and gas wells, but also affects the degree of damage to oil and gas layers and the operation effect of various operations in the future. Therefore, it is very important to improve the economic benefits of exploration and development to do a good job in protecting oil and gas layers during drilling. [0003] When drilling oil and gas layers, under the action of positive pressure difference and capillary force, the solid phase of drilling fluid enters the oil and gas layer, causing pore throat blockag...

AI Technical Summary

Problems solved by technology

[0003] When drilling oil and gas layers, under the action of positive pressure difference and capillary force, the solid phase of drilling fluid enters the oil and gas layer, causing pore throat blockage, and the liquid phase enters the oil and gas layer and interacts with the rock and fluid of the oil and gas layer, destroying the original balance of the oil and gas layer, thus Induce the potential damage factors of oil and gas layers, resulting in the decrease of permeability

[0004] Existing mud cannot meet the complex requirements of oil and gas formations