Evaluation of Two Thermal Methods in Offshore Heavy Oilfields Development

Comparative study on development effect of multi-thermal fluid and steam huff and puff was done to provide the basis for optimum thermal technique selection in offshore heavy oilfields development.Geologic model for single thermal single well was established according to the actual reservoir parameters using numerical simulation method and in which two injection schemes were set:the same injection enthalpy value,and the same injection rate and combining with the field development pilot.The characteristics and effects of the two thermal techniques were comparatively analyzed.The numerical simulation result showed that the recovery rates of multi-thermal fluid and steam huff and puff methods were 18.3% and 12.4%,at the same injected enthalpy(4.3×1013 J),and those for two thermal methods are 17.5% and 13.3% at the same injection rate(227 m3/d),the recovery rate of from multi-thermal fluid was 1.3 to 1.5 times of that from steam huff and puff method.The deliverability from multi-thermal fluid huff and puff well was 1.5 times of that from steam huff and puff well in the field pilot.So the multi-thermal fluid huff and puff,which can enhance oil recovery more than steam huff and puff,is more suitable for offshore heavy oil fields development.