【摘要】 随着油气勘探向深部地层和低渗透油气藏的延伸,对固井水泥浆性能尤其是水泥环的力学性能提出了更高的要求。针对目前固井用纤维所存在的问题,研究了碳酸钙晶须这一无机矿物纤维对固井水泥浆性能的改善作用。实验包括:1晶须水泥浆的流变性和失水量等常规工程性能;2晶须水泥石的1 d、3 d、7 d、14 d和28 d抗压强度、抗折强度和劈裂抗拉强度,使用6265型机械性能测试仪,在不破坏水泥试样的情况下测试了水泥石的抗压强度和杨氏模量发展;3使用5265型静胶凝强度测试仪,测试了水泥浆的静胶凝强度发展,以评价其防气窜性能;4晶须水泥石的孔径和渗透率测试;5用扫描电镜对水泥石微观形貌进行观察,探讨了增强机理。结果表明:1晶须水泥浆工程性能良好;2碳酸钙晶须显著改善水泥石的力学性能,晶须加量为10%时,水泥石28 d抗压强度、抗折强度和劈裂抗拉强度提高33.34%、45%和39.28%;3碳酸钙晶须水泥杨氏模量发展稳定,静胶凝强度发展迅速,防气窜性能良好;4晶须加量为10%时,孔隙度较空白试样降低23.4%,渗透率下降14.3%;5增强机理在于碳酸钙晶须的桥联、控制微裂纹产生和扩展及纤维拔出耗能作用,减缓裂纹的产生和延展。更多还原

【Abstract】 As the oil and gas exploration in deeper formation and extension of lower permeability reservoirs,cement slurry performance can meet the higher requirements,especially the mechanical properties of cement ring. In view of the present cementing problems with fibers,calcium carbonate whisker,an inorganic mineral fiber,was studied on the properties of cement slurry. The experiment included:( 1) tested the conventional engineering performance such as the rheology and water loss of oil well cement slurry;( 2) Maintained and tested the compressive strength,flexural strength and tensile strength of whisker cements for1 d,3 d,7 d,14 d and 28 d; explored the compressive strength and young’s modulus of cement stone without destroying the cement sample by using 6265 type mechanical properties tester;( 3) studied the anti-gas channeling performance and static gel strength of cement slurry by using 5265 type static gelling strength tester;( 4) the pore size and permeability test of the whiskercement stone;( 5) explored the reinforcing mechanism of whisker cement through observing cement microstructure with scanning electron microscopy( SEM). The results showed that:( 1) the whisker slurry had a good engineering performance;( 2) Calcium carbonate whisker can significantly improve the mechanical properties of cement stone. When the whisker was added to 10%,the compressive strength,flexural strength and splitting tensile strength increased by 33. 34%,45% and 39. 28% for 28 d;( 3)the young’s modulus developed stability and the static gel strength developed rapidly which guaranteed a better anti-gas channeling performance;( 4) the porosity was lower 23. 4% than the blank sample,and the permeability decreased by 14. 3% with added 10% whisker;( 5) calcium carbonate whisker reinforcing mechanism mainly includes the bridging,control micro crack extension and fiber pull-out,which can slow down the occurrence and extension of the crack,and improve the initial crack strength.更多还原