It`s been 95 years since oil production started to be performed by means of injection of water into oil deposits. As a result of water injection, formation pressure remains at the required level and oil is displaced out of pores. Traditionally, injection wells are used for injection of water and other displacement agents, production wells are used for extraction of oil out of the formation. According to reservoir development plan, the distance between bottomholes of injection and production wells may vary from 200 to 800 m. This traditional spacing pattern remains the same in many fields while depths of oil formations in new and existing fields become greater, now the average depth is 3-4 kilometers and more.

Considering great depths of formations it is cost-effective to replace two wells with one well with functions of two wells: injection and production wells.

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