Method for calculating single-well controlled reserves of water-producing gas well

Abstract

The invention discloses a method for calculating single-well controlled reserves of a water-producing gas well. The method comprises the steps that a relation model of gas-water two-phase relative permeability and water saturation of a to-be-measured well is established, wherein the gas-water two-phase relative permeability includes gas-phase relative permeability and water-phase relative permeability; according to the relation model of the gas-water two-phase relative permeability and the water saturation, a relation model of current formation pressure and water saturation is determined, anda single-well controlled reserve calculation model is deduced by combining a water-drive reservoir material balance equation; and a pressure value and a water saturation value of the to-be-measured well are collected, and according to the collected pressure value, water saturation value and state parameters of the to-be-measured well, the single-well controlled reserves of the to-be-measured wellare solved through the single-well controlled reserve calculation model. Through the method, the complex water invasion amount calculation process in the dynamic reserve calculation process is avoided, the calculation process is simple, data requirements are simple, collection is easy, and adaptability is wider; and the method is high in calculation precision and has high popularization value.

Description

technical field [0001] The invention relates to the technical field of oil and gas exploration and development, in particular to a method for calculating the controlled reserves of a single well of a water-producing gas well. Background technique [0002] The calculation of single well controlled reserves of gas wells is an important work in the process of gas field development. Through the calculation of controlled reserves of single wells of gas wells, the production ratio of single wells of gas wells can be optimized and the water influx can be estimated, so as to formulate waterproofing and water control measures for the next step. Especially in the development process of high-sulfur and water-bearing gas reservoirs, the seepage characteristics of gas phase and liquid phase are relatively complicated, and are affected by factors such as sulfur deposition. Dynamics play a vital role. [0003] At present, many scholars at home and abroad have carried out in-depth research...

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Problems solved by technology

[0003] At present, many scholars at home and abroad have carried out in-depth research on the calculation of the controlled reserves of gas wells (dry gas wells and water-producing gas wells), which are mainly divided into the following three categories: Type I is the material balance method, but for For water-producing gas reservoirs, the calculation process of water influx is cumbersome. The main calculation models include Schilthuis model, Van Everdingen&Hurst model and Fetkovich model. The method of type III requires the production of gas wells to reach a pseudo-steady state, so it cannot be applied to gas wells with a short production time; the method of type III is an analysis method of production instability, but this type of method is greatly affected by water production in the process of calculating the controlled reserves of a single well , the single-well controlled reserves of water-producing gas wells cannot be calculated

At the same time, the above three types of methods all require in-depth research on the gas-water seepage law of water-producing gas wells and the productivity formula of gas wells. If the influence of sulfur deposition and other factors is considered, the seepage law becomes more complicated and cannot be applied to high-sulfur water-producing gas wells. Calculation of Controlled Reserves of Single Well

[0004] During the development of sour gas fields, the gas wells in the reef-shoal complex area and the beach area produce water successively, and the trend of water production is relatively obvious. This is also a general feature of organic reef gas reservoirs. At present, the method for calculating the controlled reserves of a single well of a water-producing gas well is cumbersome and requires There are many conditions to be met, and the calculation process involves cumbersome water inflow calculations, so it cannot be widely promoted

Taking the Yuanba high-sulfur gas field as an example, with the gradual reduction of gas well pressure, water production of more than half of the gas wells is gradually obvious, and all of them are dominated by formation water. Due to the complex seepage law and cumbersome productivity formula, it is impossible to calculate the gas wells accurately and in large quantities. The control of reserves by a single well brings certain difficulties to the dynamic analysis, productivity prediction, reasonable production allocation and water invasion countermeasure research of water-producing gas wells, and also brings challenges to the dynamic analysis of the entire sour gas field

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