A new method for evaluating the injection effect of chemical flooding  

作　　者：Jian Hou Yan-Hui Zhang Nu Lu Chuan-Jin Yao Guang-Lun Lei 

机构地区：[1]State Key Laboratory of Heavy Oil Processing, China University of Petroleum [2]School of Petroleum Engineering, China University of Petroleum [3]CNOOC LTD., Tianjin Bohai Oilfield Institute

出　　处：《Petroleum Science》2016年第3期496-506,共11页石油科学（英文版）

基　　金：the financial support from the National Natural Science Foundation of China (Grant No. 51574269);the Important National Science and Technology Specific Projects of China (Grant No. 2016ZX05011-003);the Fundamental Research Funds for the Central Universities (Grant No. 15CX08004A, 13CX05007A);the Program for Changjiang Scholars and Innovative Research Team in University (Grant No. IRT1294)

摘　　要：Hall plot analysis,as a widespread injection evaluation method,however,often fails to achieve the desired result because of the inconspicuous change of the curve shape.Based on the cumulative injection volume,injection rate,and the injection pressure,this paper establishes a new method using the ratio of the pressure to the injection rate（RPI） and the rate of change of the RPI to evaluate the injection efficiency of chemical flooding.The relationship between the RPI and the apparent resistance factor（apparent residual resistance factor） is obtained,similarly to the relationship between the rate of change of the RPI and the resistance factor.In order to estimate a thief zone in a reservoir,the influence of chemical crossflow on the rate of change of the RPI is analyzed.The new method has been applied successfully in the western part of the Gudong 7th reservoir.Compared with the Hall plot analysis,it is more accurate in real-time injection data interpretation and crossflow estimation.Specially,the rate of change of the RPI could be particularly suitably applied for new wells or converted wells lacking early water flooding history.Hall plot analysis,as a widespread injection evaluation method,however,often fails to achieve the desired result because of the inconspicuous change of the curve shape.Based on the cumulative injection volume,injection rate,and the injection pressure,this paper establishes a new method using the ratio of the pressure to the injection rate（RPI） and the rate of change of the RPI to evaluate the injection efficiency of chemical flooding.The relationship between the RPI and the apparent resistance factor（apparent residual resistance factor） is obtained,similarly to the relationship between the rate of change of the RPI and the resistance factor.In order to estimate a thief zone in a reservoir,the influence of chemical crossflow on the rate of change of the RPI is analyzed.The new method has been applied successfully in the western part of the Gudong 7th reservoir.Compared with the Hall plot analysis,it is more accurate in real-time injection data interpretation and crossflow estimation.Specially,the rate of change of the RPI could be particularly suitably applied for new wells or converted wells lacking early water flooding history.

关 键 词：Ratio of the pressure to the injection rate Rate of change of the RPI Injection efficiency Chemical crossflow 

分 类 号：TE357.46[石油与天然气工程—油气田开发工程]