Forecasting zones of high porosity in clay rocks of Eastern Ukraine

The new approach for clay rock differentiation using porosity value is proposed. This approach is based on the correlation coefficient values analysis for acoustic impedance and shaliness. The correlation between acoustic impedance and shaliness is absent for shale and shaliness rocks with small values of porosity. For rocks with porous shale the correlation coefficient between acoustic impedance and shalines can be higher than correlation coefficient between acoustic impedance and porosity. In this case the shale fraction of rocks is a carrier of porosity. This fraction controls distribution of acoustic impedance values at the physical level.

The prognosis of the clay rocks zones with increased porosity was done. For solution of this task the 3D seismic data is used. The total area of investigations is about 200 square kilometers. The geophysical data obtained from three wells at the investigation area are used as well. Constructed model of rocks physical property coincides with drilling and testing data in these wells. Geological section of this area is characterized by high amount of clay rocks and small amount of sandy layers. These sandy layers have not industrial flow rate of hydrocarbons.