水平井不动管柱无限级分段重复压裂技术研究

针对水平井传统重复压裂管柱技术存在的施工排量低、级数少等问题,研制了一种适用于139.7mm(5英寸)套管的新型水平井不动管柱无限级分段重复压裂管柱。该管柱结构配套工具中,插管采用反向旋转丢手;悬挂式封隔器具有套管双向锚定和环空密封的双重功效;自解封型封隔器锁块阻挡机构采用可溶性金属材料制成,压后可实现封隔器自解封;球座和滑套采用卡槽配合限位,卡槽尺寸为级差设计,可在轴向实现无限级。利用TADpro软件模拟和预测不同施工排量下的管内流体摩阻和井口泵压,结果表明:新型压裂管柱最大允许排量是传统管柱的2.0～5.4倍。该新型管柱可实现水平井分段重复压裂。

Research of Stage Unlimited Refracturing Technology for Horizontal Well Without Pulling String

The problems of low discharge capacity,limited stages in the conventional refracturing string technology for horizontal wells has been focused and a new type of stage unlimited refracturing technology for horizontal well without pulling string,which is suitable for 51/2 in casing was studied.Within the scope of the pipe string structure matching tools,the intubation with reverse rotation releasing,while the hold down packer has the dual functions of the casing double-side anchor and the annulus sealing.The self-sealing packer locking block with soluble metal material,releases the packer after fracturing.The ball seat and the sliding sleeve with clamping grooves structure has been adopted to match and limit,while the size of the clamping grooves is differentially designed and the infinite-level can be realized in the axial direction.The TADpro software was applied to simulate and predict fluid friction and wellhead pump pressure in the pipes with different construction displacement.The result shows that the maximum allowable displacement of the new fracturing string is 2.0~5.4 times over conventional pipe string.The new pipe string can meet the field production demand of horizontal wells for staged refracturing with increasing production and digging efficiency.