碳酸盐岩油藏高温超深井高导流自支撑酸化压裂技术

Acid Fracturing Technology for High-conductivity Unpropped Fractures in Ultra-deep Wells with High Temperature in Carbonate Reservoirs

针对超深井酸化压裂改造形成的酸蚀裂缝易闭合、导流能力衰减快的问题,合成了新型酸化压裂屏蔽保护剂,并对其自聚性、油溶性、黏附性等关键指标进行了评价。该技术通过对水力裂缝表面非连续的、暂时性屏蔽,阻断酸岩反应,实现酸蚀裂缝由点支撑向面状支撑转变,裂缝有效支撑高度可提高3倍。采用CFD软件模拟优化了屏蔽保护剂颗粒在裂缝中的分布形态,确定了屏蔽保护剂用量、注入排量、携带液种类等工艺参数。该技术在塔河油田高温超深井进行了应用,压裂后效果表明,屏蔽剂在地层温度下黏附性、油溶性达到设计要求,自支撑裂缝的导流能力和有效期明显延长。该技术对提高超深井酸化压裂效果具有重要意义。

In response to the problems of easy closure of acid-etched fractures and rapid attenuation of conductivity caused by acid fracturing in ultra-deep wells,a new acid-fracturing shielding protectant was synthesized and evaluated for its key indicators such as self-agglomeration,oil solubility and adhesion.This technology blocks the acid-rock reaction by discontinuously and temporarily shielding the surface of the hydraulic fracture,and realizes the transformation of acid-etched fractures from point support to surface support,and the effective support height of the fracture can be increased by 3 times.CFD software simulation was used to optimize the distribution pattern of shielding protective agent particles in the fractures and to determine the process parameters such as shielding protective agent dosage,injection and displacement rates,and carrier fluid type.The technology was applied to ultra-deep wells with high temperature in Tahe Oilfield.The results after fracturing showed that the adhesion and oil solubility of shielding agent at formation temperature met the design requirements,and the conductivity and service life of unpropped fractures were significantly prolonged.This technology plays an important role in the improvement of acid fracturing effect in ultra-deep wells.