Study On Deep Profile Control Technology Of Water Injection Wells In Shannan Block 3

Through the analysis of the geological characteristics of the reservoir in Shannan 3 block and the problems of water injection development,it is considered that the formation heterogeneity of the block is serious,with the deepening of water injection development,the contradictions between layers and layers become more and more prominent,the common liquid amount and water cut well increased.In order to improve the water drive efficiency,the deep profile control technology of water injection wells in this block was studied.Based on the investigation of water injection profile control technology at home and abroad,combined with the actual situation of the reservoir,the combination profile control system with polymer flooding and surfactant flooding was analyzed,and the indoor formula of deep profile control system was studied.A compound gel profile control agent and compound surfactant suitable for reservoir conditions of Shannan 3 block was developed,a flexible resistance to salt granular profile control agent was screened,and the laboratory performance evaluation of profile control agent system was proceeded.The laboratory evaluation results show that the compound gel profile control agent has the characteristics of good selection of sealing characteristics,high plugging rate,good heat resistance and salt resistance and good thermal stability,The screened retarding dilatation viscoelastic particle profile control agent has the characteristics of slow expansion speed,good salt tolerance,good water retention and suspension performance.The compound surfactant has the performance properties of 10-3mN/m order of magnitude.On the basis of laboratory experiments,the composite gel profile control agent,flexible resistance to salt particle profile control agent and compound surfactant are combined slug,and the profile control process design suitable for Shannan 3 block was developed.The Shannan 3-29 well group was selected in the block,and the pilot test of deep profile control was carried out.The water injection starting pressure after deep profile control measures was increased from 9.5MPa to 16.0MPa after deep profile control measures.The water absorption index decreased from 29.2 m3/MPa to 14.8 m3/MPa and decreased by 49.3% before the measures.The cumulative output of the four wells corresponding to the borehole within six months reached 900 tons.The pilot test results shown that the developed composite gel profile control agent,compound surfactant,and screened flexible and salt-tolerant particle profile control agent could meet the needs of deep profile control in Shannan block 3 reservoir,played a good total increased oil effect,and has a certain extension role.