Optimization Study Of Injection - Production Parameters On Steam Injection Production In Du 229 Block

Du 229 block in Liaohe oilfield has been put into operation since 1998 and it reached the peak production of 83.2×104 t/year,however it decreased sharply in the subsequent years and dropped to 26.5×104 t/ year in 2007.After nearly 10 years of vertical well steam soak production,the total recovery ratio has reached 21.1% which achieved 90.13% of the calibration recovery ratio,there was no further exploitation potential for vertical well steam soak production.In order to alleviate the sharp decrease trend of annual oil production and further improve the recovery ratio,a variety of steam injection test methods were put into effect in Du 229 block since 2007,mainly including vertical well steam flooding,horizontal well steam soak,SAGD and so on,where vertical well steam flooding and horizontal well steam soak brought more ideal test results and might become the main trend of the future exploitation methods for Du 229 block.According to the three dimensional geological model?well pattern arrangement and distribution of pressure?temperature and oil saturation after the end of vertical steam soak for the vertical steam flooding and horizontal well steam soak test areas,the influence patterns of injection-production parameters on the recovery ratio of the vertical steam flooding and horizontal well steam soak test areas were firstly studied using numerical reservoir simulation and the best value range of each injection-production parameter was qualitatively determined.Then the injection-production parameters were optimized using the orthogonal experiment design method on the basis of best value range of each injection-production parameter and the final best values combination of the injection-production parameters were obtained.Finally,the optimization results were verified based on the production data from the beginning of the test to the end of 2015.For vertical steam flooding,the optimized injection-production parameters increased the total oil production and recovery ratio of the test area by 4.09% and 1.25% respectively,for horizontal well steam soak,the corresponding increases were 2.19% and 0.71%,which proved the correctness and feasibility of the optimization results.