DEVELOPMENT METHOD FOR TWO PRODUCTION FACILITIES OF MULTILAYER OIL DEPOSIT Russian patent published in 2014 - IPC E21B43/14 

FIELD: oil and gas industry.

SUBSTANCE: method includes identification of production facilities with terrigenous type of reservoir developed by producers and injectors, optimisation of the development system, oil production through producers, injection of working fluid through injectors. According to the invention two production facilities are identified, which are to be the second and the seventh facilities counting from below for ten facilities at the whole deposit with share of more than 85% of remaining oil reserves. Development of the second facility is made up to the final stage, when high water cut of the product is obtained, while the seventh facility is developed up to the third stage. Rates of development are aligned for the facilities. For this purpose ratio of the producers at the second and seventh facilities are set within limits of (3.3-3.5):1 and the ratio of injectors - within limits of (6.0-6.5):1. At the second facility vertical and horizontal producers and injectors are drilled with the following ratio of vertical and horizontal wells - (2.5-3.0):1. Offshoots and horizontal offshoots are drilled from well in the non-operating stock in the ratio of (3.0-3.3):1. 10-12% of well in the operating stock at this facility are converted into injectors. At the seventh facility vertical producers of small diameter and injectors are drilled with the ratio of (3.2-3.4):1. 2.5-3.5% of producers from the united stock of the second and seventh facilities are converted to the seventh facility. 0.4-0.5% of injectors from the stock at the second facility is converted to the second and seventh facilities using equipment for dual injection. Offshoots are made from wells of the nonoperating stock in the volume of 2.9-3.1% of the common stock of producers at the seventh facility. Associated water is used for maintenance of reservoir pressure. For the first three years at the second facility 7-8% of new wells of the total planned quantity are drilled and 16-18% offshoots and horizontal offshoots are made of the total planned quantity. For the fourth year and further on 2.1-2.5% of new wells of the total planned quantity are drilled annually and 5-7% offshoots and horizontal offshoots are made of the total planned quantity. For the seventh facility for the first three years 14-15% of new wells of the total planned quantity are drilled. During following years, annually, 2.5-3.5% of total planned quantity of new wells is drilled, 7-11% of offshoots and horizontal offshoots are made, and 2.6-3.2% of wells are converted from the second facility of the total planned quantity to be converted from the second facility.

EFFECT: improving uniformity of the facilities development at multilayer deposit and increasing oil recovery.

1 ex