凝胶承压堵漏技术在普光地区的应用

The Application of Mud Loss Control under Pressures with Gelled LCM in Puguang Area

普光地区承压堵漏技术存在裸眼段长、漏层及缝洞孔喉尺寸难确定、存在张开性裂缝和岩石骨架承压能力低等难点,桥塞堵漏的效果不理想。因此对桥塞堵漏剂进行改进,通过引入凝胶聚合物和胶结剂形成凝胶堵漏剂。性能评价结果表明,凝胶堵漏剂对不同漏失通道的适应性好,能与地层胶结成高强度的封堵层,对由5～20mm砂粒组成的砂床或10～30mm石子模拟漏层均具有很好的封堵能力,封堵层的承压能力大于9MPa;该剂的弹性变形能力、膨胀堵塞和化学胶结作用能有效提高材料进入和驻留漏层的能力。凝胶堵漏技术在普光地区4口井中进行了试验,成功率为100%,取得了很好的承压堵漏效果,证实了该技术具有现场适应性好和堵漏强度高的特性。

In Puguang area,mud losses occurred in long open holes,in which the position of mud loss zones and the sizes of the fractures of the formation were difficult to determine.Small fractures will open or became larger under pressures which were always high.The strength of the basal rocks was relatively low.Failure in mud loss control in this formation was frequently encountered in the past.To solve the problem,a gelled lost circulation material(LCM),in which a gel polymer was added,was used in the control of mud losses in this area.Laboratory experiments were done on the performance of the LCM mud using sand beds(sand sizes between 5-20 mm)or simulated loss zone(made with gravel sized in 10-30 mm).Under a pressure of 9 MPa,good results were obtained using the new LCM.This LCM was successfully used in four wells in Puguang area.