ORRNEO Technology (Single Commingle Development of Several Production Zones)
Authors: Leonov Vasiliy A. , Sharifov Makhir , Garipov Oleg 
Published: December 2007

The paper presents the problem of the usage of "intelligent wells" with multi packer arrangement. The "intelligent well" with multi packer systems enable companies - operators to adjust parameters of a reservoir in a mode of real time and to provide selective operation of particular deposits through the section without running the well.

The multihorizon oil fields are effectively developed by such wells on Western Siberian oil fields. It is possible simultaneously-separately or alternately to withdrawal and inject into several exploited objects and also to keep account and the control of extraction of a fluid and injected agent through one lift. Simultaneous -separate development of multihorizon oil fields using multi packer arrangement is a new direction in development and perfection of the theory and practice of oil production.

At the optimization of oil recovery [i] process both current production maximization and oil recovery maximization of all reservoirs under development are implemented as a criterion. It is obvious that the more production zones are allocated the higher oil recovery can be obtained per total number of reservoirs. However, regardless of oil recovery enhancement at zones subdivision this approach is restrained by economic limitation, first of all, by a number of drilled wells. There is another alternative method of subdivision of development zones without drilling additional wells (several commingled zones for separate zones or several interlayers for separate interlayers) without drilling of additional wells. This way, the contradiction between economic side and conservation of mineral resources when choosing operational objects can be resolved using the single-commingle technology [ii].

Geological simulation is performed by applying a software package using seismic surveys data, field geophysics (logs), core analysis and taking into consideration of a theory on formation features of a reservoir under review [i]

Traditional approach of geological model parameters determination (porosity, permeability, net pay thickness, OWC location, rock water-retaining capacity, volumetric shaliness, etc.) as per logging data (SP, apparent resistivity, induction, nuclear, acoustic logging, MRIL, etc.) in reservoirs with complicated structure not always give open-ended answers. For example, due to polymineral rock composition and forming of deep zones of process liquids penetration into the zone while evaluation of saturation properties. While determination of fluid loss properties of reservoir rocks upon logging surveys data considering lithologic and petrophysical core studies except functional correlation between porosity, permeability and reservoir saturation, correlations between the following parameters are also determined: permeability and horizon effective net pay; residual water saturation and permeability; initial oil saturation and hypsometric offset from OWC; permeability and diffusion-adsorption activity, etc.

2D and 3D seismic is widely used for revealing geological structure and productive reservoirs faults and 4D seismic (3D seismic within some period of time) - for determination of interphases movement between fluids and stagnation zone borders, which are not covered with filtration.

Geochemical methods are applied more and more during hydrocarbon deposits surveys. Particularly, oil system basic elements - source rock, migration ways, reservoirs, covers, traps are defined with the help of geochemical correlation using modern analytical data base - Rock-Eval kerogen pyrolysis, gas chromatography, chromatography-mass spectrometry, isotop-mass spectrometry. Upon maximum concentration of hetero-organic compounds (asphaltenes, tars, sulphur and nitrogen-organic compounds, paraphines, high-molecular aromatic hydrocarbons, etc.) the sources location of oil ingress into a deposit are determined. the additional of these sources are: the higher initial production rates, formation pressures and temperature and also net pay thicknesses of the section and number of oil saturated productive layers.