川西中浅层气藏双封隔器三层分压合采投产管柱研究与应用

川西中浅层气藏属低孔、低渗、多层系气藏,部分井单层压裂改造不能满足经济有效开采要求,需要采用双封隔器分压三层,压后不动管柱合采投产.针对压差式封隔器工具组合分层压裂管柱存在的问题,研究开发出了一套适合于川西中浅层气藏的多层分压合采管柱,该管柱采用水力式Y241双封隔器工具组合,提高了压裂管串的可靠程度,特别是开发出了低密度钢球配合双滑套喷砂器,在压裂施工结束时不用动管柱而通过双滑套喷砂口实现了三个产气层的有效连通,满足了压后不动管柱三层合采直接投产的需要.在2006年7月至2007年7月间,应用该工具组合在川西中浅层气藏成功地进行了10口井共30层的压裂施工,工具应用成功率达100.0%,为川西中浅层多层系气藏的进一步高效开发奠定了重要基础.

DEVELOPMENT AND APPLICATION OF LAYERING FRACTURING STRING IN SHALLOW-MIDDLE GAS RESERVOIR OF WEST SICHUAN

Shallow-middle gas reservoir of west Sichuan belong to a low porous,low permeability and multi-zones gas field,single zone fracturing stimulation in some wells can't meet the requirement of effective production so that a new method has to be used,i.e.fracturing three zones dividually with double Y241 packers and production without moving the string after fracturing.In consideration of the problems existing in separate zones fracturing string with differential pressure packer combination,a string system suited for shallow-middle gas reservoir of west Sichuan has been developed which makes use of Y241 hydraulic packers combination,thus enhanced the reliability of the fracturing string.Especially,the packer combination adopted low-density steel-ball and double sliding sleeve sand injection valve,therefore three zones could be produced together without tripping out of the string.From July of 2006 to July of 2007,30 layers of 10 wells in shallow-middle gas reservoir of west Sichuan were treated by using this string combination with a success rate of 100%.