Study on Productivity Multiple Factor of Steam Huff and Puff Thermal Recovery in Offshore Heavy Oilfield

摘要

The Bohai Sea has a large amount of heavy oil resources,and the special heavy oil with viscosity greater than 350 mPa·s needs thermal recovery because of its low productivity and low recovery.At present,offshore heavy oil testing only carries out routine testing,which can not directly obtain the production index under thermal recovery conditions.It is necessary to convert the conventional testing productivity into thermal recovery productivity.Thermal recovery productivity multiple factor is the key to conversion,but there is no technology to determine the productivity multiple factor at present.By using reservoir numerical simulation method,a comprehensive quantitative characterization technology of thermal recovery productivity multiple factor considering reservoir physical properties,fluid properties and injection rate,injection steam temperature and injection steam dryness is developed,and the chart of steam stimulation productivity multiple factor relationship and multi-factor formula are established.The prediction error is less than 5% verified by wells in offshore L oilfield.The research results can provide guidance and basis for production of steam huff and puff thermal recovery wells under different conditions.