The use of branched horizontal wells at the Zhanazhol field to increase oil recovery

Abstract

The research presents an analysis and experiment on horizontal wells of the Zhanazhol field, an analysis of the operation of horizontal wells is carried out. The analysis of the factors affecting the efficiency of oil production by horizontal wells is carried out, experimental and industrial methods of operation are proposed for further implementation of horizontal well technology. The design of the construction of branched horizontal wells has been carried out. The purpose of this work is to substantiate the feasibility of switching to fundamentally new development systems using horizontal wells to increase the flow rate of liquid hydrocarbons using the example of the Zhanazhol field. The results of pilot tests of drilling branched horizontal wells to increase oil recovery at the Zhanazhol field are summarized. At the Zhanazhol field, the maximum capacity of oil reservoirs reaches about 190 m. The average capacity of oil–saturated reservoirs is about 3 m. There are intervals of impermeable interlayers in the productive formation. The thickness of most impermeable layers varies within 5 m. An impenetrable layer with a thickness of about 10 m is spreading widely. This affects the nutrition and energy supplementation of oil reservoirs, resulting in a rapid decrease in oil production and reservoir pressure. For example, the average daily flow rate of oil with a 15 mm fitting is more than 150 tons, but the current flow rate of oil with a 7 mm fitting is 52 tons (horizontal well No. 2407). The technology of drilling branched horizontal wells in certain geological conditions allows: to obtain initial flow rates 10 times higher than the flow rates of conventional wells with an increase in the cost of drilling only 1.5 - 2 times; to ensure accumulated production over 10-15 years of operation 10 times higher at the cost of extracted oil 3-5 times lower than for neighboring conventional wells; to increase the total oil recovery from productive formations by 20-30 percent; to thin the well development grids.