The Key Technology Research of the Water Injection System Energy Saving for Super Low Permeability Reservoir in Changqing Oil Field

Abstract

With the characteristics of low permeability, pressure and abundance, it's extremely hard to exploit the super low permeability reservoirs in ChangQing oil field. For this reason, the water injection recovery technique has been widely used. Analysis showed that a serious problem of high energy consumption exist in the water injection system, the power consumption of which accounts for about 44%. And the energy cost of pump units reach up to 43%, it's the highest energy consumption link in the system. In this paper the load rate classification method (LRCM) is firstly adopted to statistical analyze water injection stations, which are divided into the owing and over load rate stations. As a result, the owing load rate stations accounts for 83.8%, with a serious phenomenon of the Big Horse Pull A Small Carriage, causing the large-scale backflow in the station, and the efficiency is low, the energy consumption is on the high side. Aimed at water injection stations with different load rate, the methods of reasonable shutting down the pumps, pump replacement, optimizing the transmission ratio and piston size, as well as the speed control technology have been used to make the outlet flow and actual demand reasonable matching. The test result shows that the energy saving technology is well targeted, simple, practical and low cost. The pump units’ efficiency improves obviously, the consumption reduces by 10%, which greatly improve the oilfield economic benefits.