Method and device for judging single-well water invasion situation of water-carrying gas reservoir and controlling gas well production

Abstract

The invention discloses a method and a device for judging a single-well water invasion situation of a water-carrying gas reservoir and controlling gas well production. The method for judging the single-well water invasion situation of the water-carrying gas reservoir comprises the steps of taking Gp(Ppi-Pp) / (Ppi-Ppwf) as x coordinates, taking q / delta Pp as y coordinates, and drawing a first diagnostic curve; taking Gp as the x coordinates, taking Pwf / Z as the y coordinates, and drawing a second diagnostic curve; taking tca as the x coordinates, taking q / delta Pp as the y coordinates, and drawing a third diagnostic curve; respectively carrying out gas well water invasion judgment on the first diagnostic curve, the second diagnostic curve and the third diagnostic curve; giving a gas well water invasion conclusion by integrating judging results, wherein Gp is the cumulative gas production in current time, Ppi is a pseudopressure form of initial pressure of a gas well, Pp is the average pseudopressure of an oil reservoir in the current time, Ppwf is a pseudopressure form of BHFP (Bottom Hole Flowing Pressure) of the gas well, q is the daily gas production of the gas well, delta Pp is equal to Ppi-Ppwf, Pwf is the BHFP of the gas well, Z is a gas bias factor, and tca is a pseudotime function. According to the method and the device, disclosed by the invention, the reliability of judging the single-well water invasion situation of the water-carrying gas reservoir can be increased, and the production of the gas well can be reasonably controlled.

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...

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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

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