Electronic Control Separate Layer Flooding – A Case Study in Jilin Oil field

Abstract Oil production from low-permeability oil reservoir plays a more and more important role in oil production. Separate layer waterflooding is an effective method in improving the oil recovery, but because of low adsorptivity of low-permeability reservoirs, single layer flow rate is too small to be measured accurately, the interlayer interference makes it more difficult to get right flooding rate, and the smaller water nozzle is easily blocked by contaminant. A new electronic control water flooding technology is presented in this paper. Powered by DC battery, the system has a gear motor acting as adjustment element, flat nozzle as flush control, swing-rod flowmeter as test gauge, a pressure sensor installed behind nozzle to supervise the reservoir pressure, and a temperature sensor to supervise the downhole temperature. The whole system is controlled by microcomputer, realizing automatic calibrate of flow. Synchronous testing and adjusting process has been invented to eliminate the interlayer interference, and the nozzle will be opened fully periodically to let out the contaminant. This new technology has been tested in Jilin Oilfield and proved to be effective. The swing-rod flowmeter can test small flow rate as low as 1.5m3/d, which can meet the requirement of low-permeability reservoir flooding. Synchronous testing and adjusting process has solved the interlayer interference problem and improved the testing and adjusting efficiency greatly, a testing and adjusting period can be finished in 5 minutes. The periodically opened nozzle solves the block problem and prevents the system from failure because of contaminants. The new electronic control water flooding technology provides an effective way for low-permeability oilfield flooding. The newly invented swing-rod flowmeter has solved downhole flow measurement problem, and the synchronous testing and adjusting process has addressed the interlayer interference problem and improved the calibration efficiency greatly.