Study On Recovery Law Of Chemical Assisted Cyclic Steam Injection In Bohai Offshore Deep Heavy Oil Reservoir

Chinses offshore oil production are mainly located in Bohai Sea,and its total reserves of heavy oil account for nearly half of them.At present,most of the offshore heavy oil reservoir in Bohai area are developed by cold production method.Cyclic steam injection,as a widely used and effective heavy oil development method,is hopeful to be one of the most effective development method for Bohai Sea heavy oilfield.It is necessary to carry out offshore heavy oil steam stimulation of research and field testing.Based on the production data of thermal recovery test in C oilfield,this essay analyzes the dynamic production performance of two steam stimulation wells.The production characteristic of offshore heavy oilfield are compared with some onshore steam stimulation projects.The characteristics of offshore heavy oil steam stimulation development index are summed up.Besides,we also discuss the main problems of offshore heavy oil thermal recovery.By using numerical simulation,we establish a thermal recovery model of the appropriate test area for evaluating the effect of different insulation parameters on wellbore heat loss.At the same time,this model also be used to evaluating the effect of different steam injection parameters on development effect.Because of its characteristics of offshore oilfields,making it more difficult to change the recovery mode from steam stimulation to steam flooding.Based on the numerical modeling research of steam stimulation for C oilfield,we study on nitrogen foam assisted steam stimulation and viscosity reducer assisted steam stimulation.Both of these two methods can improve the steam stimulation's development effect.Using orthogonal experimental design,the two chemical assisted steam stimulation development programs were optimized.