Influence of heterogeneity indicators on productivity index prediction efficiency (on example of carbonate reservoir deposits in the Ural-Volga region)

The purpose of the work is to present the analysis results of the research conducted to determine the influence degree of heterogeneity indicators on the efficiency of productivity index prediction using the differentiated analysis for three large stratigraphic units confined to carbonate reservoirs of the Volga-Ural oil and gas province. At the initial stage of solving the problem, two data samples were taken, which consisted of geological and field information of various completeness. Using the formulas received before, a search for analogous objects for a smaller sample of deposits was carried out. Next, having different input data, the authors obtained analytical dependences for predicting the cleaning time of the bottomhole formation zone for three large systems. The latter were later modified using widespread and single accounting of four parameters of complex heterogeneity characterizing porosity and permeability of productive formations. The application criteria were identified for the obtained models to solve the problems of oil field development. The conclusions regarding the cleaning mechanisms of the bottomhole formation zone and productivity index prediction in various geological systems were drawn. Particular attention was paid to the need for in-depth analysis of the hierarchical representation of the identified three systems: by tiers and horizons in order to find the patterns of parameter changes within small groups and a generalized assessment of the effect of heterogeneity on the productivity index.

carbonate reservoirs, well production ratio, stratigraphic system, heterogeneity of the geological structure of objects, porosity and permeability of productive formations, geological and statistical modeling