The Bazhenov formation is the largest oil and gas source formation in the West Siberian oil and gas bearing province, whose reserves are classified as hard-to-recover. The Bazhenov formation deposits are both the most significant hydrocarbons source rocks in the province and an independent oil and gas reservoir. Formation has a complex geological structure, which directly affects the mobile hydrocarbon reserves heterogeneous distribution. Analysis of implementing approaches experience to the unconventional reservoir development regarding to Bazhenov formation reservoirs shows that the reservoirs distribution is characterized by lateral variability and is not controlled by a structural factor. The lack of sure signs of reservoir evolution identifying zones and assessing their productivity is one of the most important risks achieving successful Bazhenov reserves development. The sweet spot zones are interpreted to be laterally limited areas in which the source rock maturity degree is sufficient to form liquid and moving hydrocarbons in sufficient quantities to operate wells that will be profitable.
This paper presents a method for localizing Bazhenov formation promising zones which is based on the kerogen transformation model with a prediction of the achievable pore pressure, taking into account the material balance and rock stress. The approach is based on a consistent physical and mathematical model that describes the kerogen conversion kinetics with a subsequent increase in pore pressure in the source rock and the formed liquid hydrocarbons vertical migration into the nearest reservoirs due to auto-fluid fracturing of the clay tight formation-barriers for the oil source rock. The simulation result is visual map of prospective areas for the Bazhenov formation development that allows to determine the priority well drilling areas.
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