粉煤灰降失水水泥浆在天然气井固井中的研究与应用

长庆天然气田属于低压、低渗透气田,存在承压能力较低的地层,固井设计要求全井段封固,并且采用双级双凝施工工艺。但由于用于低密度水泥浆中的漂珠生产量降低,价格上升,研究应用替代产品是固井技术发展的方向。在一级领浆中研究应用了粉煤灰水泥浆体系,其性能和固井质量可完全满足固井要求。粉煤灰水泥浆体系价格低和固井质量优良,使其成为漂珠水泥浆体系的替代配方。

Research and Application of the Fly Ash as a Fluid Loss Reducer in Natural Gas Well Cementing

The reservoir in Changqing Oilfield is low-pressure low permeability in nature. Wells with weak formation in a certain section is required to be cemented from the bottom to the surface, and a two-stage cementing, separable setting cement slurry technology should be used. A substitute for hollow micro-spheres is expected to satisfy the need for oil and gas well cementing because of the recent decrease in production of the hollow micro-spheres (and hence a high cost). In our research, cement slurry containing flay ash is used in the first stage cementing. The performance of the cement and the cementing job quality are all quite satisfactory. Furthermore, the fly ash slurry is inexpensive. It is expected that the fly ash will become a successor of the hollow micro-sphere both technically and economically.