环江油田抗高矿化度水质压裂液体系研究

Research of Fracturing Fluid with High Salinity Resistance in Huanjiang Oilfield

关键词:  环江油田  压裂液  高矿化度  螯合助溶剂  螯合稳定剂

Key words:  Huanjiang oilfield  fracturing fluid  high salinity  chelate solvent  chelate stable agent

摘要:

环江油田在前期的压裂施工过程中存在压裂液体系抗剪切、携砂性能差的问题,严重影响了对储层的有效压裂改造。通过室内试验分析后发现该区压裂配液用水中含有浓度高于正常值数倍的Ca2+、Mg2+等金属离子,其能与胍胶高分子基团作用,导致胍胶不能在水中充分溶胀或溶解,并出现分层和沉淀物。为此,研发出了抑制水质高矿化度、促进胶液溶胀、提高压裂液抗剪切能力的AH-Z螯合助溶剂与AH-W螯合稳定剂,大大减小了高矿化度金属离子对压裂液性能的影响,提高了压裂液的抗剪切、携砂性能,从而形成了有效稳定的交联冻胶,保证了压裂顺利施工。

Abstract:

The shearing resisted and poor sand-carrying performance of fracturing fluid has seriously affected the effective fracturing reconstruction of the reservoir in the Huanjiang oilfield in the early-stage fracturing process.Laboratory analysis shows that water in this area contains several times higher concentrations of Ca2 +,Mg2 + and other metal ions than normal water.The metal ions can interact with guar gum polymer group,which results in difficulties in swelling or dissolving in water,and the occurrence of stratification and sediment.The chelate solvent AH-Z and chelate stable agent AH-W were developed.They can inhibit high salinity,promote guar gum swelling,increase fracturing fluid shear-resised capacity,and greatly reduce the detrimental effects of the high salinity metal ions on the performance of fracturing fluid as well.Consequently,they can improve fracturing liquid shear resistance and sand-carrying capability,and promote to form an effective and stable cross-linked gel ensuring the smooth fracturing process.