The Study And Application Of Bottom-water Drive Reservoir Exploration With Horizontal Well In ShaXi Block Of Huabei Oil Field

In recent years, drilling horizontal wells has been becoming an important method of increasing production for oil and gas reservoirs development all over the word. Horizontal well technology is believed to be suitable for the big effective thickness and good reservoir physical property and better fracture development in the Shaxi area.On the basis of a bottom-water drive reservoir in Shaxi zone of Huabei Oilfield, the bottom-water drive reservoir developed by horizontal well technology is researched and applied.From the aspect of the basic principle of infiltrating fluid (mirror reflection and superposition principle), its flow pattern and productivity and breakthrough time are studied in this thesis. Guided by the principle of mass balance, the change relations of current oil zone thickness and current water zone thickness with time is derived .Then, the critical stable condition of water cresting in horizontal well is deduced according to the principle of force balance. By applying reflection method and Muskat's basic formula of a line array of wells, a formula describing the critical output of a line array of horizontal wells which are on the top of a bottom-water drive reservoir is derived. The equivalent filtration resistance method based on the bottom water driving vertical speed is adopted to derive the calculating model of critical production pressure difference and the calculating method of critical production capacity from the aspect of the principle of water cresting.Through above-mentioned research, the research and application of bottom-water drive reservoir developed by horizontal well technology are carried out in Shaxi zone of Huabei Oilfield. First, the geological design of horizontal well including the distance between the horizontal well and oil-aqueous interface, the length of horizontal segment, the direction of horizontal segment in the reservoir and the methods of horizontal well completion are studied. Secondly, the parameters of horizontal well has been optimized which include the determination of the critical production ,the reasonable productivity and critical pressure difference of the horizontal well. Finally, the type of the production decline is analyzed. It is derived from the study that the horizontal well technology in the bottom -water reservoir exploration is superior to the vertical well and it can slow down bottom water coning effectively, prolong the breakthrough time of oil well ,advance the production of the single well greatly, prolong the time of stable yield and boost the economic benefits effectively. It can be used to direct the application and deployment of horizontal wells in the process of bottom-water drive reservoir development.