Forecast of terrigenous rocks reservoir properties based on the acoustic research results under the conditions of alternating pressure (on the example of Volodymirivska area in Volyn-Podillya region)

Abstract

The features of the original laboratory research techniques and study of void space structure according to the petrophysics data in variable pressure conditions have been considered.

The original ultrahigh pressure facility was used for experimental petrophysical studies. Laboratory research process was held at increasing pressure from 1 MPa to 60 MPa and inversely with its reduction to 1 MPa. Interpretation of laboratory tests was carried out using the technique that makes it possible to invert the speeds data into the structure of the void space (to define void formats and their concentration in the samples).

The regularities of petroacoustic properties change of Volyno-Podillia region, Volodymyrska area, Cambrian terrigenous rocks depending on the applied pressure have been studied. Analyzing the results of petrophysical studies (velocity of longitudinal waves, the coefficient of porosity in variable pressure and density, speed of transverse waves in atmospheric conditions) based on techniques developed by the author, a quantitative void distribution of different formats in the studied rocks was established.

Separate rock groups were allocated, which correlate by acoustic, capacitance and petrographic parameters. The types of rock porosity were quantitatively defined.

Determination of rock void space structure for different pressure conditions makes it possible to trace the quantitative changes of rock porosity types with pressure changes, as well as to allocate and forecast the prospect of complex structure terrigenous reservoir rocks at large depths