煤层气水平井完井用塑料筛管优化设计

塑料筛管完井技术能够提高煤层井壁的支撑能力,并能有效解决粉煤灰堵泵问题。在介绍塑料筛管完井工艺的基础上,对塑料筛管的几何参数进行了设计,采用计算流体动力学方法,使用Fluent软件对塑料筛管进行了压力损失计算,并对计算结果进行了分析和优化。分析结果表明,过流面积比越大压力损失越小,缝宽越小压力损失越小,筛眼越长越有利于降低压力损失;筛眼宽度对长条形筛管强度的影响很小,筛管变形位移随筛眼长度的增大而增大,60°相位角的筛管变形位移小且分布均匀。建议采用相位角呈60°、筛眼宽度为7 mm、筛眼长度为23～26 mm,过流面积比为3%～4%的筛管设计方案。

Optimized Design of Plastic Screen Pipe for Coal Bed Methane Horizontal Well Completion

The plastic screen pipe can improve the supporting capacity of coal bed methane(CBM) well wall and effectively prevent fly ash from plugging the pump.The completion technology of plastic screen pipe was first introduced and then the geometric parameters of the screen pipe were designed.The computational fluid dynamic method and the Fluent software were adopted to conduct a calculation of the screen pipe pressure loss.The calculation result was analyzed and optimized.The analysis shows that the greater the open area ratio,the less the pressure loss;the smaller the slot width,the less the pressure loss;the longer the screen mesh,the more favorable to the reduction of pressure loss.The screen mesh width has little effect on the strength of long strip screen pipe.The deformation and displacement of the screen pipe increase with the screen mesh length.The deformation and displacement of the screen pipe with the phase angle of 60°are less remarkable with an even distribution.It is suggested that the design scheme of the screen pipe be adopted with the phase angle being 60°,the screen mesh width being 7 mm,the screen mesh length being 23～26 mm,and the open area ratio being 3%～4%.