Heavy oil reservoirs in Henan oilfield are shallow, thin-bed-ded, viscous and sporadic. The shallow and thin-bedded heavy oil reservoir in 0 area of field where steam flooding pilot was performed is a typical heavy oil reservoir in Henan field. In pilot steam flooding, the average depth of oil reservoir is 356m, its thickness is 5.4 m, total thickness ratio is 0.53 and the dead oil viscosity at reservoir temperature is 18,800 MPa centre dot s. The field uses inverted 5-spot well pattern. The distance between injectors and each producer is 100 m. There are 4 well groups including 13 injectors and producers. Based on the recovery of 29.1percent, OSR of 0.549 in cyclic steam stimulation, steam flooding pilot obtain the recovery of 22.4percent and OSR of 0.232. The project is considered as a better example for technical and economical success. The paper analyses the production performance of steam flooding. According to the geological properties and production profiles, the technology involved for improving steam flooding effectiveness in this type of reservoirs are: conversion time from steam soak to steam drive, attractive measures of steam stimulation, steam slug injection, and selecting pumps to satisfy the field condition.
展开▼
