摘要
固井施工中 ,由于某些原因在水泥石中形成许多初始缺陷 ,在射孔、压裂等作业产生的冲击载荷作用下 ,初始缺陷的裂纹尖端处会形成高度的应力集中 ,随着应力水平的发展 ,裂纹将迅速扩展 ,形成裂纹、裂缝 ,造成油气层段窜槽 ,给射孔后开发和改造挖潜等增产措施带来极大困难。通过研究和分析水泥石环发生破坏的情况及应力变形特征 ,研究出水泥石塑性较高而脆性较小的抗冲击韧性水泥浆。对水泥石抗压强度、抗折强度、动态弹性模量、泊松比、最大扰度、动态断裂韧性和射孔损伤程度等参数的测试表明 :水泥浆中加入改性纤维、聚合物对水泥石的动态力学性能有明显提高 ;水泥石抗压强度越高 ,脆性越大 ,弹塑性、断裂韧性越弱 ;采用抗冲击韧性水泥浆 ,水泥石塑性较高而脆性较小 ,水泥环具有一定的抗冲击性和韧性 ,可减小井下作业对水泥环的损坏 ,降低、节省修井费用 ,延长油气井的寿命 。
Initial bugs which lead to crannies forming by impact load of perforating and fracturing exist in cement stone owing to some reasons during cementing. And the crannies expand rapidly with increasing of stress and forming fractures, therefore causing channeling in oil or/and gas segment. These reasons give severe difficulties in stimulations. Impact resistance toughness cement slurry system which is high plastic and low brittle was developed based on wide analysis of breakage of cement stone and its stress deformation. The performance factors of the cement stone such as compressive strength, rupture strength, dynamic elastic modulus, Poisson’s ratio, maximum perturbation, dynamic toughness and perforation damage were tested and the results showed that dynamic mechanics property of the cement stone was improved remarkably because adding differential fiber and polymer into the cement slurry; compressive strength was positively correlative with brittleness and negatively correlative with elastic and tough properties. Using the impact resistance toughness cement slurry system in cementing, the cement stone became better elastic property and low brittle, as well as certain impact resistable and tough. Thus cement stone damage caused by working can be prevented, cost of mending well can be reduced and working life and recovery efficiency of oil or/and gas wells can be increased.
出处
《钻井液与完井液》
CAS
北大核心
2004年第1期36-39,共4页
Drilling Fluid & Completion Fluid
关键词
抗冲击
韧性
水泥浆
性能
cement slurry
impact resistance
toughness
performance testing
EOR
Changqing oilfield
