Method for water-flooding abandoned condensate gas reservoirs

Abstract

The invention discloses a method for water-flooding abandoned condensate gas reservoirs. The method includes performing full fluid PVT (pressure-volume-temperature) analysis first to complete long-core displacement experimental analysis. The long-core displacement experiment mainly includes the steps: selecting core samples on site; testing basic physical-property parameters of cores; splicing the core samples into a long core for displacement experiment, performing natural energy failure experiment, performing displacement in flooding, acquiring recovery rate of water-displacing condensate oil and condensate gas under different conditions according to the experiments, and comparing to determine the waterflood pattern which is most satisfactory to the requirement of increasing recovery rate of condensate gas reservoirs on site; and compiling a condensate gas reservoir water-flooding scheme according to indoor experiment results. The problem that existing depletion development of condensate oil-gas reservoirs is fast in energy decline, causes underground condensate oil loss and is low in production level is solved. Reasonable water-flooding speeds and water-flooding modes are optimally selected by the method and used for water flooding of abandoned condensate gas reservoirs, so that recovery rate of condensate oil-gas reservoirs is effectively increased.

Description

technical field [0001] The invention relates to a method for developing a condensate gas reservoir, in particular to a method for improving recovery by water injection in an abandoned condensate gas reservoir. Background technique [0002] Condensate gas fields have occupied a very important position in my country's gas fields, and their development has also attracted more and more attention from the petroleum industry. However, condensate gas fields are a very special and complex type of gas fields. On the one hand, it has high economic value because it can produce natural gas and condensate oil at the same time; on the other hand, during the development process, due to the retrograde condensation of condensate gas, the gas phase Medium and heavy hydrocarbons will undergo interphase mass transfer and phase change, condensate condensate oil and condense in a large amount in the formation porous medium from the gas well to the reservoir far away, forming pressure drop funnel...

AI Technical Summary

Problems solved by technology

[0006] The traditional domestic condensate gas reservoir development theory believes that water poses a great threat to condensate gas reservoirs, especially in gas reservoirs with thin gas layers, flat structures, good physical properties, and active edge and bottom water. The leading edge is directly flooded to the gas well, which leads to the premature shutdown of the gas reservoir, increases the abandonment pressure of the gas reservoir, and loses the resources of the gas reservoir

In addition, when water enters the condensate gas reservoir, it is easy to form the Jamin effect and cause water lock, making it impossible to recover the remaining condensate oil and gas

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