The Study Of Cement Technology Of Suqiao Buried Hill Underground Gas Storage In Huabei Oilfield

The production well of underground gas storage possess the dual function of injection and withdrawal natural gas,withstand heavy alternation changes under the intensive injection and production in multi-cycle underground gas storage operation.Therefore,the technical requirements especially cement quality requirement of well drilling and completion are settled highly above the general gas production well,which play an important role in protecting the underground gas storage operation with long period,high intensity and safety.Huabei Suqiao underground gas storage met many cement technical problems in early stage of construction,led to long drilling time and high cost.Although caprock cement got success operation,long drainage of horizonal wells with big casing annulus are still confronted with challenges.The study of cementation is conducted to improve cement quality,ensure this kind of well have a good usage result.Suqiao buried hill deposited deep,which is characterized of low formation stress coefficient,high temperature and leakage,bring the cement difficulties like big well bore size and long sealing intervals.The paper detailed summarize a series of toughness cement slurry system with high temperature tolerance and a good protection of gas flee and formation leakage to against the cement difficulties.Based on the research on high temperature suspension mechanism of slurry,increase the toughness of cement and pressure balance cement,the comprehensive work of additive including toughness materials optimization and evaluation was carried out.The flush fluid and spacer fluid system is developed to solve the contamination problem of drilling fluid,spacer fluid and slurry,enhance the cement quality and operation safety by upgrading the flush effectiveness of small annulus,long sealing intervals at low pump rate.The thesis focusses on anti-pollution mechanism of spacer fluid,narrate the method to optimize this newly-typed agent,and have a good match with oil-based drilling fluid.The cement technical measures integrated well bore preparation,raise up displacement technology,pressure balance cement technology,suit for Huabei Suqiao buried Hill underground gas storage.This set of cement methods could settle down the high-temperature,leakage and long sealing intervals problems,so as to guarantee the safety and quality of cement operation.