METHODOLOGY FOR CALCULATING THE CUMULATIVE OIL RECOVERY AFTER APPLYING THE CONFORMANCE CONTROL TECHNOLOGY
| Autor: | Tatyana N. Kovalchuk, Aleksandr Y. Gilmanov, Aleksandr P. Shevelev |
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| Jazyk: | ruština |
| Rok vydání: | 2022 |
| Předmět: | |
| Zdroj: | Известия Томского политехнического университета: Инжиниринг георесурсов, Vol 333, Iss 6, Pp 131-139 (2022) |
| Druh dokumentu: | article |
| ISSN: | 24131830 2500-1019 2413-1830 |
| DOI: | 10.18799/24131830/2022/6/3588 |
| Popis: | The relevance of the study is caused by the fact that at present, a significant part of the large deposits of the Russian Federation are at a late stage of development. Due to the fact that the production of associated water requires large additional investments, water cut is the reason for increasing oil cost. For the majority of oil wells, the production of highly water-cut products is economically unprofitable. Therefore, technologies are used to reduce the value of water cut, for example, the conformance control technology. The main aim of the study is to determine the water cut after the application of the conformance control technology, to assess the additional oil production taking into account the criterion proposed earlier, to verify the model using an example of a real field. The objects: large high-watered oil fields, in particular the fields of Western Siberia. The methods of physical and mathematical modeling were used in the work. Corey correlations were used to calculate the values of the relative phase permeabilities of oil and water. To determine the volumetric flow rate of oil and water to the central well in a circular homogeneous reservoir, the classical Dupuis formula was used. An assumption was introduced about the way of permeability changes in the interlayers near the production well after the impact. It was taken into account that for the production well, the value of the difference in the standard deviations of injectivity before and after the impact, which was the same for the injection well, is preserved. This difference is considered one of the possible criteria for the effectiveness of well treatment with a suspension and was calculated by the authors in earlier studies. In order to calculate the average time after which the effect of polymer injection stops in the horizontal direction, the Buckley–Leverett equation was taken into account. In order to determine the time after which vertical flows begin, the piezoconductivity equation was taken into account, which describes the distribution of pressure in the reservoir for fluid depending on time and coordinates. Thus, an expression was obtained for the time during which an increase in production rate will be observed and additional cumulative oil production is calculated. Results. Thus, the paper proposes a method for calculating the water cut of produced oil after well treatment with a polymer-dispersed system. Since the low mobility slurry forms a zone of reduced permeability near the bottom of the well in the most water-saturated interlayers, the resulting water cut is reduced. The value of the difference between the final and initial water cut makes it possible to judge the effectiveness of the measure. The greatest effect from the redistribution of flows is observed at standard deviation values from 0,45 to 0,65 for the selected model data. It is shown that the proposed method makes it possible to estimate at what initial values of water cut one can consider the use of the conformance control technology as a method of enhanced oil recovery. The difference between the initial water cut and the calculated one is 3–6 % of the initial water cut. This is consistent with field data. The model was verified on the example of a real field. The resulting values for additional cumulative production after the application of the conformance control technology are sufficiently accurate. |
| Databáze: | Directory of Open Access Journals |
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