Publication de 4 numéros par an
ISSN Imprimer: 2151-4798
ISSN En ligne: 2151-562X
Indexed in
CONTROLLING WATER PRODUCTION IN FRACTURED RESERVOIRS WITH CAVITIES USING WATER INJECTION
RÉSUMÉ
This paper reports on a special water-control strategy, controlling water production by injecting water in the producer (CIWIP), which is used in fractured reservoirs with cavities. The operation is a huff-and-puff approach: the oil producer with a high water cut is converted to the water injector for a certain period of time, is shut in for another period of time, and then is open for production. Compared with the operation of shutting in the well and then re-opening it, water injection in the CIWIP approach not only helps increase the oil rate but, more importantly, it reduces the water cut, which is opposite of the conventional recognition from single-well water cycling. A recovery mechanism of the CIWIP is proposed on the basis of a three-layered conceptual model and validated for the first time through numerical simulation in this paper. The conceptual model consists of a high-permeability upper zone, a low-permeability middle zone, and a bottom aquifer. Through water injection and well shut-in periods, pressure in the upper zone is built up and the reservoir oil and injected water are segregated. As a result, oil production is increased from the upper zone and the overall water cut is reduced. Numerical simulation of Darcy-Stokes equations demonstrates that cavities in the upper zone significantly accelerate water and oil segregation and improve the effectiveness of the CIWIP. Based on the CIWIP mechanism, the paper further provides the criteria for well selection and the keys to a successful CIWIP. A potential candidate for the CIWIP is a fully/partially sealed reservoir with high productive zones and large space for oil and water exchange. In addition, the existence of cavities in the highly productive zones is another consideration since cavities facilitate the water injection process and have a significant impact on the reduction of the well shut-in time period.
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Peng Xiaolong, Liang Baosheng, Du Zhimin, Wang Minwei, Practical simulation of multi-porosity reservoirs through existing reservoir simulator, Journal of Petroleum Science and Engineering, 151, 2017. Crossref