液氮伴注水基泡沫压裂液技术在苏77井区的应用

APPLICATION OF AQUEOUS FOAM FRACTURING LIQUID WITH LIQUID NITROGEN LNJECTION TECHNOLOGY IN SU 77 WELL FIELD

介绍了苏77井区的储层特征,并指出压裂改造过程中面临的主要难题:粘土含量高、压力系数低、返排困难、残渣伤害。针对难题,苏里格气田普遍采用液氮伴注水基泡沫压裂液技术,增压助排,减少储层伤害。该压裂液100℃剪切稳定性好,能有效防止粘土膨胀运移,液氮泡沫稳定,有助于增加地层能量,提高自喷返排率。通过现场使用表明,采用液氮伴注水基泡沫压裂液技术,适当提高平均砂比、变排量施工、提高液氮伴注比例以及全程伴注等措施,不断优化施工参数,有效满足了苏77井区低压低渗气藏的压裂试气施工,并取得一定成效。

This paper introduces the reservoir characteristics of Su 77 well field,and points out the main problems such as high clay content,low pressure,backflow difficulty and residue damage in the process of fracturing.Due to the problems,the technology of aqueous foam fracturing liquid with liquid nitrogen injection was widely used in Sulige gas field.The fluids systems have the excellent abilities to resist shear at 100℃ and can effectively prevent the clay from swelling or migration.The static foam can help to increase the power of the formation and improve backflow ratio after fracturing.Practical application results show that construction parameters are constantly optimized,such as properly enhanced average proppant concentration,variable displacement construction and improvement on the ratio of liquid nitrogen as well as the whole course injection,so the aqueous foam fracturing liquid with liquid nitrogen injection technology can effectively meet the fracturing and gas testing work for gas reservoir with low-pressure and low permeability in Su 77 well field,and certain results have been abtained.