On the Technical Limits of Steam Flooding in Common with Large Well Spacing——By Taking Es44 of Block Cao 4 in Le'an Oilfield for Example

Es44 of Block Cao 4 in Le'an Oilfield was a common heavy-oil reservoir with weak edge water,it was developed by using steam soaking with well space of 200m×283m.It entered into a stage of multiple soakings and it was faced with some problems,such as rapid cyclic production decline,rapid pressure reduction and low oil recovery.To greatly improve oil recovery ratio in the block and in consideration of economic profit,reservoir engineering analysis and numerical simulation methods were used to study the feasibility of steam soak at space of 200m×283m and validity time of steam soaking.The method of steam flooding are determined,the technical limits of steam soaking are established,It is predicted that 19.1% oil recovery ratio should be enhanced in steam flooding,it provides reference for steam flooding in large space of wells in the similar reservoirs.