Polymer drag-reduction agent for shale gas reservoir quick water fracturing fluid and preparation method thereof

Abstract

The invention provides a polymer drag-reduction agent for shale gas reservoir quick water fracturing fluid. The polymer drag-reduction agent is prepared from acrylamide and a salt-resisting functionalmonomer through a reverse phase emulsion polymerization method; a production technology is simple, the production cost is low and the reaction efficiency is high; a product belongs to an acrylamide quaternary copolymer and the viscosity-average molecular weight is 3 million to 15 million; the product has an excellent mineralization resisting effect and the adaptability of the drag-reduction agentis extremely increased; furthermore, the prepared fracturing fluid can adopt high mineralization stratum water and stratum flow-back water and is effectively utilized, so that the field utilization cost is reduced, water resources are sufficiently utilized and the environment is effectively protected; moreover, emulsion of the drag-reduction agent is stable, has good solubility and easily flows back.

Description

technical field [0001] The invention belongs to the field of fracturing fluid additives for shale gas fracturing technology, and particularly relates to a polymer drag reducing agent for slick water fracturing fluid in shale gas reservoirs and a preparation method thereof. technical background [0002] Areas rich in shale gas are often areas with very poor water resources. According to the data of the World Resources Association, China has the world's largest recoverable shale gas resources, but these resources are mainly distributed in the Tarim Basin, Sichuan Basins and other places where water resources are extremely scarce. However, in the process of slick water fracturing in shale gas reservoirs, 15% to 75% of the flowback water flows back to the ground, causing serious pollution caused by direct discharge. In response to the call of the state to protect the environment and save water resources, the solution using backflow water or formation water has been implemented ...

AI Technical Summary

Problems solved by technology

For the water quality with high calcium and magnesium ions, for example, the calcium ion content of the flowback water in Marcellus area is 8500-24000mg / L, and the magnesium ion content is 933-1790mg / L. Drag reducer for magnesium ions

Although Kemira has developed a polyacrylamide emulsion system drag reducer with a molecular weight as high as 2 to 4×10 8 , capable of 23 x 10 4 It still has a high drag reduction rate under mg / L salt water, but under the condition of too high calcium and magnesium ions, the performance is still greatly affected

Images