Comprehensive evaluation and prediction method for enrichment favorable area of dense oil in lacustrine basin

Abstract

The invention discloses a comprehensive evaluation and prediction method for the enrichment favorable area of dense oil in a lacustrine basin. The method comprises steps of performing data collection and processing and acquisition of key data; according to the longitudinal superposition relation of different rocks in the logging lithology profile, making the configuration relationship of source and reservoir clear and establishing the single well lithofacies mode; using the single-well cloud ratio, TOC data to form the cloud-to-field ratio contour map and the TOC contour map, overlapping the cloud-to-field ratio contour map, the TOC contour map and the source and reservoir relation plane configuration map, and determining the lithofacies plane distribution map; and overlapping vitrinite reflectance contour map on the basis of the lithofacies plane distribution map, and referring to the dolomite thickness contour map to perform the comprehensive evaluation and prediction of the enrichment favorable area of the dense oil. The beneficial effect is that the method is simple in operation and high in accuracy, and can clearly and comprehensively reflect the plane distribution rule of high quality reservoir, high quality source rock and its mutual configuration relationship; and the economic cost is low and the operability is strong.

Description

technical field [0001] The invention relates to an evaluation and prediction method, in particular to a comprehensive evaluation and prediction method for favorable areas of tight oil enrichment in continental lake basins, belonging to the technical field of petroleum exploration. Background technique [0002] With the continuous improvement of conventional oil and gas exploration, the difficulty of exploration is increasing day by day, and the cost of exploration is increasing day by day. Finding new replacement areas has become one of the important issues in oil and gas exploration today. Unconventional oil and gas, especially tight oil and gas, has the characteristics of rich oil and gas resources, great exploration potential, and low exploration degree. With the continuous improvement of exploration technology and deepening of understanding, tight oil and gas has become an important oil and gas replacement field. Since tight oil and gas are distributed in a large area, l...

AI Technical Summary

Problems solved by technology

Since tight oil and gas are distributed in a large area, low abundance, and diffuse in the fine-grained sedimentary areas of semi-deep lakes to deep lakes, and are locally enriched in sweet spots, the sweet spots have the typical characteristics of strong concealment, complex distribution rules, and difficulty in finding them. At present, the evaluation of tight oil and gas is mostly focused on the study of the vertically distributed intervals of a single well, while the comprehensive evaluation and prediction of plane sweet spot is relatively rare, and the qualitative search is mainly to find the relative porosity and permeability of high-quality source rocks. In the relatively high area, the configuration relationship between source rocks and reservoirs, the degree of thermal evolution of source rocks, and the thickness of reservoirs and other controlling factors are not considered comprehensively.

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