Salt-resistant filtrate loss reducer for grafted starch drilling fluid

Abstract

The invention relates to a salt-resistant filtrate loss reducer for a grafted starch drilling fluid. The salt-resistant filtrate loss reducer is prepared from acrylamide, 2-acrylamide-2-methyl propane sulfonic acid, sodium carbonate and starch as raw materials by the processes of raw material preparation, polymerization reaction, hydrolysis reaction and modified drying. The salt-resistant filtrate loss reducer has the advantages of relatively high compatibility, relatively high filtration reducing ability in fresh water, saline water, saturated salt water and composite saltwater drilling fluid, and high-temperature resistance; and the drilling efficiency and the oil quality can be effectively improved.

Description

technical field [0001] The invention belongs to the field of petrochemicals, in particular to a salt-resistant fluid loss reducer for grafted starch drilling fluid. Background technique [0002] In the process of oil exploitation, due to the high downhole temperature and pressure in deep wells and ultra-deep wells, and the complex formation structure, high-pressure oil and gas layers and saline layers are often encountered during drilling, which leads to the liquid phase penetration of drilling fluid into the formation, affecting the stability and production of oil and gas layers. Quality, the current effective way to solve this problem is to add fluid loss control agent to the drilling fluid, the quality of fluid loss control agent greatly affects the efficiency and quality of drilling. [0003] The Chinese patent "A Preparation Method of Fluid Loss Control Agent for Drilling Fluid" (Patent No. ZL200910113490.5) discloses an anti-fluid loss agent, which consists of sodium h...

AI Technical Summary

Problems solved by technology

[0002]During the oil exploitation process, due to the high downhole temperature and pressure of deep and ultra-deep wells, the formation structure is relatively complex, and high pressure oil and gas layers and brine layers are often encountered during drilling. The liquid phase of the drilling fluid will seep into the formation, affecting the stability of the oil and gas reservoir and the quality of the product. At present, the effective way to solve this problem is to add fluid loss control agent to the drilling fluid. The quality of the fluid loss control agent greatly affects the drilling efficiency. and quality

[0003] Chinese patent "Preparation Method of Fluid Loss Control Agent for Drilling Fluid" (Patent No. ZL200910113490.5) discloses an anti-fluid loss Sodium phosphate, etherified starch, hydroxyethyl cellulose, polyacrylamide and water-soluble silicone oil are used as raw materials for synthesis. This method has complex process, poor temperature resistance, high equipment investment and raw material costs, and a large amount of waste liquid discharge. Conducive to environmental protection

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