This work discusses the problem of separation of effects from different EOR and well stimulation operations performed in the producing well and in the surrounding injection wells in the waterflooded development. Because of interference of effects, the true value of the main treatment might easily be overestimated, or on the contrary, underestimated. In such situations, estimate of base oil production comes to the forefront, however conventionally used draw-down curves and decline curve analysis (DCA) ignore effects from changes in bottomhole pressure before and after treatment and water injection rates.
Model studies to calculate base oil production might be a good solution, however, because of the too long run time and rapid aging of data, prompt estimate is challenging and so are the responsive remedial in-field operations.
Conventional approach to assess efficiency of stimulation treatment based on DCA is compared with the results of the numerical experiment using reservoir simulator. It has been shown that underestimation of injection wells’ effect while decline curve analysis results in considerable errors in calculation of incremental oil production.
For a prompt assessment of separation of treatments’ effects, the authors suggest using capacitance-resistance models (CRM), which are analytical solutions of the material balance equations. It has been shown that CRM models can significantly improve the accuracy of assessment of treatment efficiency. Furthermore, the offered approach makes it possible to estimate efficiency of the conformance control operations taking into consideration the actual well interference coefficients.
assessment of treatment efficiency, separation of effects, CRM, well interference, effect from formation pressure maintenance, decline curves, reservoir simulation
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Ruchkin A.A., Stepanov S.V., Knyazev A.V., Stepanov A.V., Korytov A.V., Avsyanko I.N. Issledovanie osobennostej ocenki vzaimovliyaniya skvazhin na primere modeli CRM. [Study of aspects of assessment of well interference by example of CRM model]. Newsletter of Tyumen State University. Physico-mathematical modeling. Oil, Gas, Energy. 2018, Vol. 4, No. 4. pp. 148-168. DOI: 10.21684/2411-7978-2018-4-4-148-168. (in Russian).
Bekman A.D., Pospelova T.A., Zelenin D.V. Novyi metod prognozirovaniya dinamiki obvodnennosti skvazhin s ispolzovaniem rezultatov CRMP-modelirovaniya. [New method to predict water cut schedule based on results of CRMP modeling]. Physico-mathematical modeling. Oil, Gas, Energy. 2020, Vol. 6. No. 1 (21). pp. 192-207. DOI: 10.21684/2411-7978-2020-6-1-192-207. (in Russian).
Т.А. Pospelova, D.V. Zelenin, А.А. Ruchkin, A.D. Bekman Primenenie CRM modeli dlya analiza effektivnosti sistemy zavodneniya [Application of CRM models for analysis of waterflood performance]. Neftyanaya Provintsiya, No. 1(21), 2020. pp. 97-108. DOI (in Russian)
Pospelova T.A., Zelenin D.V., Zhukov M.S., Bekman A.D., Ruchkin A.A. Optimizaciya sistemy zavodneniya na osnove modeli CRM [Optimization of waterflooding system based on CRM nodel]. Neftepromyslovoye delo, 2020, No.7. pp. 5-10. (in Russian).
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A.V. Arzhilovskiy, General Director, LLC «Tyumen Petroleum Research Center»
A.V. Arzhilovskiy, D.V. Zelenin, A.A. Ruchkin, T.A. Pospelova, A.D. Bekman K voprosu razdelenija jeffekta ot soputstvujushhih GTM s uchetom vlijanija zakachki [On separation of EOR /well stimulation effects with consideration of injection effect]. Neftyanaya Provintsiya, No. 3(23), 2020. pp.99-112. DOI https://doi.org/10.25689/NP.2020.3.99-112 (in Russian)