水平井段静止起动泵送在页岩气上倾井的应用

Application of Horizontal Section Static Start-up Pumping Technology in Shale Gas Updip Wells

为避免页岩气上倾井电缆泵送桥塞与分簇射孔联作工艺出现的复杂情况,需要先泵送完成桥塞坐封再将管串起至直井段重新泵送完成多簇射孔,这一定程度上保障了上倾井作业安全,却使得作业时效低、经济性差。详细分析了水平井段静止起动泵送过程并将其划分为“静止”“起动加速”“稳定运行”“减速”4个阶段,结合力学分析建立了泵送推力、加速度、加速时间理论计算模型,并在长宁威远页岩气区块上倾井中开展现场应用。现场应用结果表明,该技术理论模型计算精度高,设计的静止起动泵送起动临界排量、阶段排量、极限速度等参数能指导现场施工,保障上倾井泵送桥塞与分簇射孔作业安全,同时显著提高了作业时效、节约了成本。

In order to avoid the complexity of the combination of cable pumping bridge plug and cluster perforation in shale gas updip well, it is necessary to complete bridge plug setting, then pull the pipe string up to the vertical section and pump down once again, the above practices result in low time effect and poor economic benefit. For this reason, the pumping technology of static start-up in horizontal well is put forward. The process of static start-up pumping in horizontal well is analyzed in detail and it is divided into four stages:“static”,“start-up acceleration”,“uniform motion” and “deceleration”. The theoretical calculation models of pumping thrust, acceleration and acceleration time are established based on mechanical analysis. A series of field applications are carried out in the updip wells in Changning Weiyuan Shale Gas Block. Application results show that the models have high calculation precision. The parameters such as critical start-up pumping displacement, phase pumping displacement and limit speed of the static start-up pumping designed and calculated by the above theoretical models can guide the field operations. The static start-up pumping technology can ensure the safety of pumping multi-cluster perforation and bridge plug joint operation in updip wells, improve the efficiency of operation and save the cost.