The Study And Application On Fine Layered Fracturing In Wen'nan Oilfield

Wen'nan Oilfield is a complex fault-block oil and gas reservoir with characteristics of high pressure and low-permeability.The Oil In Place is 8956.16×104 tons,The low permeability reserves accounted for 70.36% of total reserves.Venant oilfield has many development series of strata,the well are widespread phenomenon of multilayer commingled production,reservoir span big,big difference between layers.With the deepening of oilfield development,the development object gradually shift to two,three types of complex fault block area reservoir,conventional measures can not mine oil and gas effectively.Statistics show that from 2011 to 2013 in 171 Wells,the implementation of fracturing increased 65200 t oil,accounted for 24.8% of production measures.Fracturing has become dominant measures of low permeability reservoir development in wen'nan oilfield.Due to reservoir burial depth,poor reservoir property,high temperature and the fracturing operation is difficult,the downhole tool demand is high,fracturing technology only stay in the single fracturing technical level in a long time,which can not highly adapt the demand of the oilfield development.Therefore,urgent need to develop fine layered fracturing technology.This paper introduces the application on Y341 two levels of two paragraphs fracturing technology and finely layered fracturing technology with Y221 top packer setting and pitching fracturing in wen'nan oilfield.Then introduces Y221 level two,"Y221 + Y111" two levels and two pieces "Y221 + Y241" two levels of three pieces fine layered fracturing technology.The three technology make full use of the advantages of the existing tools,through improvement of spray anchor and tubing Telescopic Compensator,optimize the technology of sand control and unlock.It has been widely applied.The paper mainly introduces the packer setting step by step,piecewise balance fracturing technology research and development process.Through the improvement of Y221 packer,added sand prevention leather cap on its upper,improves the performance of the fracturing string for preventing sand sticking,which is the fine balance of layered fracturing technology with the "Y221 + ZY541" two levels of two step by step setting and the balance and "ZY541 + + ZY541 Y221" triple two step by step setting.In addition,according to the particularity of low permeability reservoir fracturing in wen'nan oilfield,the paper shows a set of line layered fracturing technology with four techniques,which are the optimization of perforation interval,the optimization of proppant size,the composite blockage removal technology before fracturing and the balance of casing gel during fracturing.The application in wen'nan oilfield shows the fine layered fracturing technology can improve the success rate to 100%.The fracturing string were pulled out normally.The effect of fracturing shows a good result.This technology shows a good application prospect.