Abstract
Horizontal well technology is very effective to enhance oil production rate of single well in heavy oil reservoirs because of its large oil drainage area compared with vertical wells. However, since the influence of steam injection parameters and reservoir heterogeneity, length of steam absorption section in thermal horizontal wells is only 50m~70m by using conventional steam injection pipe string. Nowadays, length of completion section in thermal horizontal wells is generally about 200m, therefore controlled reserves in 130m~150m horizontal section can't be effectively produced by using conventional steam injection technology. In order to improve recovery effect of thermal horizontal wells, adaptive uniform steam injection technology is developed in Shengli oilfield. Based on studying and designing adaptive uniform flow regulator, steam injection parameters, number and arrangement of adaptive uniform flow regulators are optimized according to steam equipment capacity and reservoir properties, thus realizing uniform steam absorption in long horizontal sections. Reservoirs of whole horizontal section in thermal horizontal wells can be effectively produced and producing degree of controlled reserves in horizontal wells can be increased. Not only oil recovery rate of thermal horizontal wells is enhanced, but also oil recovery ratio.
