机械发泡式低密度泡沫水泥浆的实验研究

EXPERIMENTAL RESEARCH ON LOW DENSITY FOAM CEMENT SLURRY BY MECHANICAL FOAMING

延长油田地层具有多孔性和多洞性、节理发育、结构松散和渗透性强等特点,如果采用常规油井水泥进行施工,往往会造成水泥浆严重漏失、返深不够等固井质量问题,难以满足后续的油气射孔、酸压、增产及采油气等施工作业要求。为满足页岩气钻井可能遇到的低压地层固井需要,研制了一种加有中空玻璃微球的机械发泡式低密度泡沫水泥浆体系,对其密度、抗压强度、滤失量、流变性和稠化性能等参数进行了实验评价,并对泡沫水泥浆稠化性能测试方法进行了探讨。结果表明,这套低密度泡沫水泥浆体系在较低密度下(1.33~1.37 g/cm^3),仍然可以满足低压地层固井作业需要的抗压强度,其稠化曲线接近直角稠化,使其具有较好的防窜性能。经分析,这套体系可以较好地解决延页平1井低压地层因承压能力不足引起的固井问题。

Yanchang oilfield formation had the characteristics of porosity,multiple holes,joint development,loose structure and strong permeability.If using the conventional cement slurry in oil well,the slurry often causes serious leakage and some well cementing quality problems.The conventional cement slurry couldn 't meet the subsequent operation requirements,such as oil and gas perforation,acid fracturing,increase production,oil and gas production.In order to solve the cementing problems in shale gas drilling of low pressure formation,a kind of low density foam cement slurry system containing hollow glass microsphere has been developed.The density,compressive strength,fluid loss,rheological property and thickening performance of the foam cement slurry system were evaluated and the testing methods of the thickening performance were also discussed.The experiment results showed that this foam cementslurry system could meet the required compressive strength for low pressure formation under low density(1.33 ~ 1.37 g/cm3)condition,its thickening curve was near right angle thickening,and had good anti-channeling performance.Through the analysis,the system could solve cementing problems of Yanyeping 1well caused by insufficient bearing capacity.