摘要
为了解决致密砂岩气藏体积压裂作业周期长、施工成本高的问题,以四川盆地中江气田中侏罗统沙溪庙组致密砂岩气藏为研究对象,分析了致密砂岩气藏体积压裂增产机理及全通径无级滑套体积压裂工艺技术的优势,优化了裂缝间距、裂缝参数及压裂施工参数,形成了以“水平井精细布缝、净压力控制”为核心,大排量为关键的全通径无级滑套体积压裂工艺技术。研究结果表明:①水平井体积压裂施工排量越大,净压力越大,最优的裂缝间距越大;②最优裂缝间距随着储层品质变差而减小。结论认为:①为了提高裂缝复杂性,可以通过优化施工排量,以增大裂缝净压力且降低压裂成本为目的,实现体积压裂;②中江气田沙溪庙组气藏采用全通径无级滑套体积压裂工艺可以大辐度提高施工排量,针对储层垂直厚度为15~20 m的水平井,优化采用Φ101.6 mm及以上大尺寸管柱,施工排量为12 m^(3)/min,裂缝间距介于50~70 m,现场试验井天然气测试产量是邻井的3.2~4.9倍;③采用自主研发的全通径无级滑套完井管柱进行体积压裂,可以减少完井工序、缩减建井流程、降低作业成本、提高作业效率。
Volumetric fracturing implemented in most tight sandstone gas reservoirs may occur two problems of long cycle and high cost.So,some tight sandstone gas reservoirs of Shaximiao Formation,Zhongjiang gasfield,Sichuan Basin,were taken as objectives to analyze stimulation mechanism during the volumetric fracturing and its technological advantage based on full-bore infinite sliding sleeve.Then,fracture spacing and a few parameters as well as fracturing parameters were optimized,and the full-bore infinite sliding sleeve with"fine fracture distribution and net pressure control by horizontal well"as the core and large displacement as the key was developed.Results show that(1)during horizontal-well volumetric fracturing,the larger the operation displacement,the higher the net pressure,and the larger the optimal fracture spacing;and(2)the optimal fracture spacing may decrease as reservoir quality gets worse.In conclusion,to increase fracture complexity,the operation displacement shall be optimized to increase the net fracture pressure and decrease the fracturing cost,so as to realize the volumetric fracturing.In addition,after the full-bore infinite sliding sleeve applied to Shaximiao gas reservoirs,the displacement is increased greatly.As for the horizontal wells with vertical reservoir thickness of 15-20 m,the large-size pipe string of 101.6 mm and above is optimally adopted,the displacement is 12 m^(3)/min,and the fracture spacing ranges from 50 m to 70 m.And the gas production rate in certain test wells is 3.2-4.9 times that of its neighboring well.What's more,when the independently developed full-bore infinite sliding sleeve based completion string is used for the volumetric fracturing and completion,both well-building process and operation cost are reduced whereas operation efficiency is improved.
作者
王智君
邱玲
WANG Zhijun;QIU Ling(Petroleum Engineering Technology Institute,Sinopec Southwest Oil&Gas Company,Deyang,Sichuan 618000,China)
出处
《天然气技术与经济》
2021年第5期22-27,共6页
Natural Gas Technology and Economy
关键词
四川盆地
中江气田
沙溪庙组
体积压裂
大排量
全通径无级滑套
降低成本
Sichuan Basin
Zhongjiang gasfield
Shaximiao formation
Volumetric fracturing
Large displacement
Fullbore infinite sliding sleeve
Cost reduction
