METHOD FOR DEVELOPING FRACTURED-CAVERNOSIC DEPOSIT WITH GAS CAP AND UNDERLYING WATER Russian patent published in 2023 - IPC E21B43/32 

FIELD: oil and gas.

SUBSTANCE: invention relates to well development of a gas-oil deposit with complicated conditions and can be used in oil production from a deposit with a gas cap, including a gas deposit with an oil rim confined to fractured-cavernous reservoirs with lower underlying water. A method for developing a fractured-cavernous deposit with a gas cap and underlying water includes drilling a cluster of production wells, at least one, with horizontal trunks in the oil zone under the gas-oil contact, determining the physical and chemical properties of fluids in surface and reservoir conditions, determining filtration- capacitive properties of rocks in the near-well and inter-well zones, arrangement of surface infrastructure with an oil collection system for well pads and operation of wells. When operating wells, bottomhole pressure, daily flow rate of oil, water, gas, and buffer pressure are determined. After that, the multiphase inflow to wells in the formation is modelled, taking into account the coning of gas and water, multiphase flow in the interwell space, taking into account the interference of wells, multiphase flow in the trunks of production wells and the flow of products in the surface collection system with the formation of a joint modelling system. In the joint modelling system, the required pressure is provided for each cluster of production wells, taking into account the operating conditions of downhole equipment, bottomhole pressures and flow rates of the mentioned wells. Using the mentioned joint modelling system, the state of the reservoir system is predicted with flow rates and bottomhole pressures in production wells for a given period of time, which are periodically adjusted based on the actually measured data in these wells. Also, using the mentioned system, the maximum possible oil production is determined under given restrictions on gas and/or water extraction and the required pressures in the collection system for each cluster, for which the type of well operating equipment, its operating modes, and the period of its use are determined. After that, for subsequent periods of well operation, characterized by values of bottomhole pressure and daily flow rate of oil, water and gas different from the values in the previous period of time, the possibility of switching to a well operating conditions different from the conditions in the previous period of time, with operational equipment, is assessed, different from the equipment used in the previous period of time. Uncontrolled gas contamination and/or watering of the oil zone of the deposit is excluded at each period of operation using the above-mentioned modelling system, on the basis of which the periods of time for stopping well operation are also determined, preventing critical coning of gas and/or water, the need and timeliness of subsequent isolation of gas channels and/or water ingress.

EFFECT: increased oil production is ensured.

4 cl, 1 ex, 2 tbl