ANALYSIS OF BUILDING A FACIES MODEL OF A RESERVOIR USING THE RESULTS OF INTERPRETATION OF SEISMIC DATA

Abstract

Forecasting changes in the characteristics of sediment properties is an urgent task at all stages of exploration and development of deposits. Remote sensing techniques for sediment research, such as seismic surveys, are now becoming a prerequisite for a full study of the study area. The problems that need to be solved are not limited to the construction of a structural-tectonic model. It is necessary to look for opportunities to predict filtration and capacitance properties (PP) in the interwell space. This will improve the quality of forecasting reservoir development zones for complex reservoirs, which will result in optimization of production drilling and reduction in the risks of drilling unproductive wells. The deposits considered in this work are represented by terrigenous sediments. When developing oil-saturated intervals, water and gas breakthroughs are expected, which are especially typical for high-permeability intervals. The commercial characteristics of sediments depend on many factors, including formation conditions. Knowledge of the sedimentation environment greatly facilitates the task of predicting reservoir rocks at all stages of field development.The paper presents the results of constructing a facies model using the results of inversion transformations of seismic surveys and interpretation of GIS (geophysical surveys in wells). When creating a facies distribution model, a probabilistic assessment of the presence of a particular facies in the study area was used.In previous works, the facies model was accepted conceptually. Its influence on the final geological model and assessment of hydrocarbon reserves was indirect. The facies model presented in the article does not conceptually contradict the previously accepted one. That is, the concept of sediment formation has been preserved, but its influence on the geological model has changed. This allows you to more accurately display the geological structure of layers and optimize technological solutions when developing an operational facility.After the work was completed, more than thirty-five wells were drilled. Based on the results of the assessment of new wells, the percentage of confirmation of the forecast of facies distribution along the wellbore with the actual data of new drilling (facies identification according to GIS data) is more than 60–65 % for the entire study area.