Sodium carboxymethyl starch for drilling fluid and preparation method thereof

Abstract

The invention discloses sodium carboxymethyl starch for drilling fluid and a preparation method thereof. The preparation method comprises the following steps: firstly, adding 60-70 parts of starch into a blender with an interlayer, adding 8-15 parts of ethanol while stirring, adding 5-8 parts of basifier and 1-5 parts of antioxidant, heating up to 25-35 DEG C, hermetically reacting for 2-3 hours, sucking out excessive ethanol under a vacuum state, finally adding 18-33 parts of etherifying agent, hermetically reacting for 30-40 minutes, heating up to 80-90 DEG C, vacuumizing, drying until the drying loss is not greater than 10%, discharging, cooling to the normal temperature, and crushing the product into fine powder of 60-100 meshes and granules in a crusher to obtain the sodium carboxymethyl starch. The sodium carboxymethyl starch for drilling fluid disclosed by the invention belongs to biopolymers and is degradable, and the performance of the drilling fluid is stable to beneficially carry drilling chips; compared with wet process production, the production method is simple; compared with dry process production, the preparation method has the advantages that no raw material phenomenon is generated and the product quality and performance are stable.

Description

technical field [0001] The invention relates to a drilling fluid sodium carboxymethyl starch used as an oil and natural gas drilling fluid treatment agent and a preparation method thereof, belonging to the technical field of biopolymer preparation. Background technique [0002] With the continuous expansion of China's oil and gas exploration field, the drilling formation is becoming more and more complex. During the drilling process, it is often necessary to use a large amount of drilling fluid treatment agent to reduce the friction between the well wall and the drilling tool, the drilling tool and the casing, and prevent the well wall. Collapse, improve the ability of drilling fluid to carry cuttings, reduce downhole complex situations, improve the geological structure, and timely discover reservoirs, especially the geological conditions of saline-alkali wells with high salinity and high PH value, although great achievements have been made. Research progress, but there are ...

AI Technical Summary

Problems solved by technology

[0002] With the continuous expansion of China's oil and gas exploration field, the drilling formation is becoming more and more complex. During the drilling process, it is often necessary to use a large amount of drilling fluid treatment agent to reduce the friction between the well wall and the drilling tool, the drilling tool and the casing, and prevent the well wall. Collapse, improve the ability of drilling fluid to carry cuttings, reduce downhole complex situations, improve the geological structure, and timely discover reservoirs, especially the geological conditions of saline-alkali wells with high salinity and high PH value, although great achievements have been made. Research progress, but there are still some problems; such as high drilling fluid viscosity, increased shear force, low cuttings carrying capacity, high cost of drilling fluid, not conducive to the maintenance and treatment of drilling fluid on site, difficult to biodegrade, environmental pollution when drilling fluid is discarded Serious, especially saline-alkali wells with high salinity and high PH value have higher and higher requirements for environmental protection