Primary up-hole cementing technology for long interval isolation tight oil and gas wells with serious oil and gas leakage and water invasion
The tight oil and gas wells in Shulu Depression of Huabei Oilfield present such characteristics as deep reservoir burial,multiple water layers,high pressure and low permeability formation,and severe water invasion.For the formation above 3,500 m,the pressure coefficient is low with serious leakage and narrow drilling fluid density safety window,causing extremely complicated underground conditions,which brings many adverse factors to the cementing construction.The interval isolation of cement is long,the construction is difficult,and the disk is high,resulting in uncertain cementing quality.According to the formation characteristics of tight oil and gas wells and the effect factors of the cementing quality,the qualification rate of cement job quality is improved through the study on cement slurry system,flushing spacer fluid system and cementing technology,thus to meet the requirements of large fracturing job.The cement slurry system with large temperature difference,low density and high strength,as well as the cement slurry system with anti-fluid-channeling and toughness developed play roles successfully in solving the problems including lost circulation and water invasion.A set of cementing technology for tight oil and gas wells in long sealing section suitable for leakage loss and serious oil and gas invasion in Huabei Oilfield has been formed.The complex situation in the underground is greatly reduced,the cementing quality is significantly improved,and the qualification rate of cementing quality is increased from 80%to 98%at least,meeting the requirements of large-scale fracturing and later development.
tight oil and gas wellwell cementinglost circulationwater intrusionlong interval isolationprimary up-holegas channeling
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维普
