Low-residue starch fracturing fluid

• Main Authors: HE XINWEI, TIAN SHENGMIN, WANG XIAOLEI, GAO XIUJUN, ZOU PENG
• Format: Patent
• Language: English
• Published: 17.02.2016
• Subjects: ADHESIVES; CHEMISTRY; DYES; MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FORELSEWHERE; METALLURGY; MISCELLANEOUS APPLICATIONS OF MATERIALS; MISCELLANEOUS COMPOSITIONS; NATURAL RESINS; PAINTS; POLISHES

The invention discloses a low-residue starch fracturing fluid which comprises, by weight, 2-4% of a thickening agent, 0.5-2% of a clay stabilizing agent, 0.1-0.5% of a temperature stabilizing agent, 0.1-1% of a discharge aiding agent, 0.1-0.3% of a bactericide, 0.1-0.3% of a pH regulator and the rest of water, wherein the thickening agent is modified starch. Preparation of the modified starch comprises the following steps: firstly carrying out acetylation modification on waxy starch by using acetic anhydride, then carrying out phosphorylation modification by using sodium trimetaphosphate or phosphorus oxychloride, and finally spray-drying a modified product and carrying out pregelatinization treatment. The defect that content of water-insoluble substances existing in a conventional guanidine gel fracturing-fluid system and residue content after gel breaking are high and costs are high in the prior art is overcome. The modified starch thickening agent in the low-residue starch fracturing fluid has characteristics of low content of water-insoluble substances, low residue content after gel breaking and low cost.