The Study Of Cementing Technology Of Thief Formation In Xinzhuang Oilfield

The Xinzhuang Oilfield is located between Tanghe County and Miyang County of Henan Province,is one of heavy oil production area of Henan Oilfield.North three block of the field is a Complex Fault Block Oilfield which is situated the east of the Northern Slope area,Biyang Depression.Reservoirs in the field are shallow-buried,high content of super heavy oil.The formation has loose cementation,lower temperature and low displacement efficiency.The leak of cement pastes and wall collapse is easily occurred during the cementing,eventually affecting the cementing quality.Combined with the cementing technology research and development status of domestic and foreign leakage formation,this paper analyzes the geological characteristics of oilfield and Xinzhuang lithology,found in Xinzhuang oilfield cementing difficulties is the concrete manifestation of strata in the fracture development and bearing capacity,small pressure windows,as well as simple structure,long open hole section,the interlayer is complex,the construction process requirements strictly.Requirements and CSS mining scheme on the quality of cementing,slurry leakage occurred in cementing construction,cement admixture selection difficult,cementing leakage formation low displacement efficiency.In Xinzhuang oilfield cementing leakage,the cementing quality is difficult to guarantee the problem,carry out research to improve indoor technology bearing capacity of fractured formation,through sand bed filtration experiments and core bearing ability test,obtained 5#drilling fluid plugging slurry to leakage formation effectively plugging,improve the stability and bearing capacity of weak stratum,effective expand the safe density window,and finally the use of 5#(slurry +3%CY-1+1%DF-1+3%QS-2+3%SF-1)plugging slurry based on summing up a set of plugging site schemes to meet the requirements of the scene.Improved under the premise of the field pressure sealing ability,researched on the leakage formation of cement slurry system.First of all,on the rheological mechanism of cement slurry and condensation characteristics were studied,and then combined with the Xinzhuang oil field leakage formation of cement slurry system design requirements,the cement slurry thickening experiment,microsphere low density cement slurry system of indoor experiment and research,admixture and expansive agent selection,and ultimately selected 1.65g/cm3(Jiahua cement slurry formulation G high resistance cement quartz sand +PZ10%+30%+ filtrate reducer 2%W99+PZW-A10%+F27A2.0%leak resisting toughening agent dispersing agent +0.8%USZ + 1%G502).Finally,on technical research of Xinzhuang oilfield cementing leakage formation,find out a set of measures strata cementing technology in Xinzhuang oilfield and leakage,finally adopted grading cementing technology and insertion cementing technology in construction site,good effect.The results show that the low density cementing,cement slurry cementing and the optimized process is helpful to improve the cementing quality of Xinzhuang oilfield fractured formation,meet the need of oilfield development.Through a series of experiments and research show that the low density leak proof cement slurry system and cementing technology in this study is selected to solve the problem of cementing quality in Xinzhuang oilfield shallow,loose layer leakage wells,not only meet the needs of cementing operation,and improve the cementing quality of the block.Through the 10 wells in the field,the success rate of cementing construction is 100%,and the cementing quality is up to 30%.The technology has successfully solved the problem of cementing leakage in the block,improved the cementing quality,ensured the development scheme of the block is effectively implemented,It has high economic value and practical significance.