A simulation method for coalbed methane aboveground and underground coupling solution

Abstract

The invention provides a method for simulating above-ground and underground coupling solution for coal seam gas. The method includes acquiring coal seam information and pipe network information, presetting gas production rates of wells or water production rates of the wells and acquiring predicted gas production rates or predicted water production rates; building pipe network models according to pipe network topological structures and acquiring wellhead pressures by means of computation according to the coal seam information, the pipe network information and the predicted gas production rates or the predicted water production rates; building wellbore models according to relations between well bottom flow pressures and wellhead casing pressures and between pressure difference of pure gas column sections of annular spaces of oil jackets and pressure differences of mixed gas and liquid column sections and acquiring the well bottom flow pressures by means of computation according to the wellhead pressures, the wellbore models and the predicted gas production rates or the predicted water production rates; establishing coal seam gas well production equations according to material balance principles and acquiring computed gas production rates or computed water production rates by means of computation according to stratum parameters, the well bottom flow pressures and the coal seam gas well production equations; comparing the computed gas production rates or the computed water production rates to preset thresholds and acquiring capacity conditions of coal seam gas wellbores according to comparison results.

Description

technical field [0001] The invention relates to the field of fluid calculation, in particular to a simulation method for solving aboveground and underground coupling of coalbed methane. Background technique [0002] Coalbed methane fields have characteristics different from conventional natural gas fields: single well production is relatively low, large-scale, continuous development is required, and initial investment is high; coalbed methane wellhead pressure is very low. With the rolling development of coalbed methane fields and the continuous expansion of the pipeline network, the gathering and transportation pipeline network is becoming more and more complex, and the operation of each well interferes with each other and the operating parameters affect each other. Analysis and optimization bring bigger problems. The steady-state analysis of the coalbed methane gathering and transportation system is the basis for the design of the coalbed methane gathering and transportat...

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Problems solved by technology

However, there are few domestic and foreign researches on unconventional oil and gas field coupling solution and simulation, and a relatively mature theoretical system has not yet been formed.

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