Judgment of single well water invasion in water-bearing gas reservoirs and gas well production control method and device

Abstract

The invention discloses a method and device for judging the water invasion of a single well in a water-gas reservoir and controlling the production of a gas well, wherein the method for judging the water invasion of a single well in a water-gas reservoir includes: is the abscissa, with q / Δp p As the ordinate, draw the first diagnostic curve; with G p as the abscissa, with p wf / Z is the ordinate, draw the second diagnostic curve; use t ca is the abscissa, with q / Δp p is the ordinate, draw the third diagnostic curve; respectively judge the gas well water intrusion on the first diagnostic curve, the second diagnostic curve and the third diagnostic curve; and give the gas well water intrusion conclusion based on the comprehensive judgment results; p is the cumulative gas production of the gas well at the current moment, p pi is the pseudo-pressure form of the initial pressure of the gas well, is the average pseudo pressure of the reservoir at the current moment of the gas well, p pwf is the pseudo-pressure form of gas well bottomhole flow pressure, q is the daily gas production of the gas well, Δp p =p pi ‑p pwf ;p wf is the gas well bottomhole flow pressure; Z is the gas deviation factor; t ca is a quasi-time function. The invention can improve the reliability of judging the water invasion situation of a single well in a water gas reservoir and reasonably control the production of the gas well.

Description

technical field [0001] The invention relates to the technical field of gas reservoir development, in particular to a method and device for judging the water invasion of a single well in a water gas reservoir and controlling the production of the gas well. Background technique [0002] For the development of gas reservoirs with strong edge and bottom water energy, the most worrying problem is water breakthrough in gas wells. Once the gas well sees water, it will not only cause a lot of troubles in engineering aspects such as ground treatment, but also the key point is that the production capacity of the gas well will be greatly reduced, causing the gas well to be shut down prematurely due to low production, which will greatly affect the recovery rate of the gas reservoir and the final development effect. Therefore, accurate prediction of water breakthrough in gas wells in advance, reasonable control of production pressure difference of gas wells, improvement of water-free gas...

AI Technical Summary

Problems solved by technology

However, due to the strong heterogeneity of the actual gas reservoir and the continuous adjustment of the system during the production process of the gas well, the prediction of water breakthrough or water invasion in the gas well using these methods is quite different from the actual situation, and the evaluation results of various methods are quite different. , making it difficult for researchers to choose the appropriate method for water intrusion studies

There are also methods such as material balance method and gas reservoir water influx indicator curve to predict gas well water influx, but the application of this method is relatively limited, because this method requires more static pressure data points in gas well testing and has a certain degree of recovery. However, the actual gas wells have fewer static pressure test points and many wells still have a low recovery rate when water breaks through.

In addition, the well test logarithmic curve is used to predict the water invasion of gas wells. This method can achieve a good prediction of edge water water invasion, but it is difficult to predict bottom water gas reservoirs, and there are few analysis data of gas well tests, so it is difficult to Difficult to accurately predict water inrush for each gas well

Images