A single well dynamic reserve determination method for multi-stage fracturing horizontal wells in unconventional oil and gas reservoirs

Abstract

The invention discloses a method for determining the dynamic reserves of a single well in a multi-stage fracturing horizontal well in an unconventional oil and gas reservoir. From the logarithmic curve, the end time of the first radial flow is , the end time of the second linear flow is , and the time for the formation fluid to reach the quasi-steady flow; For the flow time of the upper non-horizontal well section, the short semi-axis of the elliptical drainage area of ​​the multi-stage fractured horizontal well and the major semi-axis of the elliptical drainage area of ​​the multi-stage fractured horizontal well are calculated by the following formula; and then the single-well drainage area of ​​the oil and gas well is calculated ; Finally, the single well dynamic reserves of unconventional oil and gas wells are calculated through the above data. The present invention uses the modern well test interpretation method to obtain the drainage area of ​​the single well of the oil and gas well, and combines the formula of the volume method to calculate the dynamic reserves of the single well of the unconventional oil and gas well in a better, more convenient and more accurate manner.

Description

technical field [0001] The invention belongs to the technical field of petroleum exploration and development, in particular to a method for determining the dynamic reserves of a single well in a multi-stage fracturing horizontal well in an unconventional oil and gas reservoir. Background technique [0002] With the ever-increasing demand for oil and gas resources and the increasing pressure on oil and gas resources, some unconventional oil and gas reservoirs that are difficult to develop (such as tight sandstone oil and gas reservoirs, shale gas reservoirs, multi-media carbonate gas reservoirs, etc.) more attention. Unconventional oil and gas reservoirs are rich in resources, and the total global unconventional oil resources reach 4495×10 8 t, equivalent to the total amount of conventional oil reservoir resources. Global unconventional natural gas reserves are much higher than conventional natural gas reserves, reaching 8 times the scale of conventional natural gas resourc...

AI Technical Summary

Problems solved by technology

The production decline analysis method has the following defects: (1) In the early stage of oil and gas well production, the production of oil and gas wells does not necessarily decrease with time, but may increase instead, so this method cannot be used to calculate the dynamic reserves of a single well in the early stage of oil and gas well production; (2) The production decline analysis method is used to fit the relationship curve of production change with time, which requires a large amount of historical data for fitting analysis. In the actual production process of oil and gas fields, the flow-time data of many oil and gas wells have poor regularity, and the reliability of the single well dynamic reserves determined from this is poor.

The trial and error method has the following defects: (1) The data of many wells provided by oil and gas fields are of poor quality, and it is difficult to obtain the dynamic reserves of a single well by matching with production

(2) For the production of unconventional oil and gas reservoirs, there is no stable working system, and it is impossible to perform trial and error fitting of single well dynamic reserves

[0004] In short, due to the poor quality of oil and gas well data and no stable working system in unconventional oil and gas reservoirs, the above methods cannot be used to obtain reasonable single well dynamic reserves.

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