Reserve calculation features of complex lithological screened deposits shown on the example of one of Gazprom Neft PJSC fields

Abstract

In most cases, the existing simplified geological models do not correspond to the current level of geological knowledge. The authors also faced such contradiction when calculating the reserves of BP₁₂ horizon of the Vyngayakhinskoye field.
The productive layers of the BP₁₂ horizon were plane-parallel according to well logs in previous works. However, the new drilling started to contradict the existing geological model.
Clinoform structure was confirmed as a result of a new seismogeological interpretation of the horizon internal structure. Different seismic attributes taken directly from the reflective horizons BP₁₂¹, BP₁₂² and BP₁₂³ (BP₁₅) used to outline lithological bodies. Well correlation was performed taking into account all seismic data.
Generalized facies maps for the layers give a presentation about the distribution of the thickness and reservoir properties in traced lithological bodies.
A more correct estimation of hydrocarbon reserves of BP₁₂ horizon was made using geological model based on local facial patterns.