Research And Application Of SAGD+ Vertical Well Drilling And Completion Technology In Xinjiang Fengcheng Oilfield

The Fengcheng Oilfield in Xinjiang is an integral heavy oil reservoir block.Such huge oil and gas resources are in urgent need of researching new process engineering to generate productivity.Currently,the accident rate is high and the recovery ratio is unsatisfactory by adopting vertical well,conventional horizontal well and SAGD as recovery methods.Based on the investigation of the experience of SAGD horizontal wells in domestic and foreign and the reality Fengcheng Heavy Oil Reservoir Development,this paper proposes the technical design of SAGD+vertical well drilling.Also,the corresponding technical measures is proposed according to the difficulties encountered during the drilling and completion process.At present,utilizing the recovery methods of plumb shaft,horizontal wells plus SAGD technologies encountered many problems,such as being difficult to lower pump,being not easy to solve the problem of pump rod string breaking,being complicated of using double pipe operation process and electric submersible pump doesn't work well under bad conditions etc.According to what mentioned above,this paper proposes the recovery pattern: SAGD+ vertical well drilling.This recovery pattern is drilling a plumb shaft at the end of SAGD horizontal wells to make an efficient connection,and make use of the upper horizontal well to fill gas and lower horizontal well to make seepage oil production,and lifting the oil in plumb shaft.Based on the recovery pattern of SAGD+vertical well,this paper presents the following research: 1.a shallow SGAD horizontal well wellbore trajectory model was established,which can maximally reduce the drill string friction and satisfy the drilling technology after prioritization;2.Analyzing the casing programme,drilling tool combination and drilling technology key issues,as well as designing the subject parameter,and systematically evaluate the mechanical properties and diagonal ability of drilling tool combination to make sure the drill bit dill into the oil layer according to the designed track and increase the control ability of wellbore trajectory;3.Rationalizing and improving the key process such as forging milling,reaming and connecting,as well as the design optimization for the drilling tools by using ?339.7mm casing forging and milling tool and reaming tool to realize the effective connection between 2 wells with magnetic guidance technology;4.Calculating the data during completion program,such as gravel filling,sand volume calculation and thermal stress control etc.,and making an appropriate completion plan;The above research results were applied to SAGD 11 group in block 32 and block 37 of fengcheng oil field.The crude oil output increased from 160 tons per day to 280 tons per day,achieving good social and economic benefits.The effect of on-site application proved that the way by changing horizontal wells to plumb shaft can simplify technological process and reduce accidents.Also,bigger pump delivery can increase recovery ratio and will be easy for completion program and production management.Currently the success rate of on-site experiment reaches 100%.In this paper,the research generates a set of matching tech which is suitable for shallow ultra-heavy oil SAGD horizontal well drilling in Xinjiang Oilfield.It discovers an efficient and workable way for the development of Xinjiang heavy oil reservoir,and has the important significance to promote Xinjiang overall target construction and “Belt and Road” energy supply.