A Method for Determination of Statistical Inversion Parameters of Braided River Delta Reservoirs

Abstract

The invention relates to a method for determining statistics inversion parameters of a braided river delta reservoir, which is characterized by comprising the steps of 1) determining the braided riverdelta sedimentary configuration pattern of a target work area; 2) conducting a seismic forward modeling test on the target work area by combining seismic data quality control and logging data qualitycontrol of the target work area based on the braided river delta sedimentary configuration pattern of the target work area, and building a forward modeling model of the target work area; 3) determining a horizon dividing algorithm, and establishing an inversion framework; 4) determining the inversion lateral range according to a braided river delta lateral range and sand body scale fitting formula; and 5) hierarchically solving the accurate sand-to-ground ratio of each single layer by adopting a Markov chain-Monte Carlo algorithm. The method is clearer in flow geological meaning, higher in inversion precision and more reasonable in description for spatial distribution characteristics of the reservoir, and has important significance for improving the geostatistics inversion precision of the braided river delta reservoir.

Description

technical field [0001] The invention relates to a seismic data inversion method in the process of predicting oil and gas reservoirs, in particular to a method for determining statistical inversion parameters of braided river delta reservoirs. Background technique [0002] At present, the proven geological reserves of deltaic reservoirs account for 52% of the total proven geological reserves in the Bohai Sea. Due to the sparse offshore well pattern, fine prediction of reservoirs needs to rely on seismic data. However, delta facies sand bodies vary greatly vertically and horizontally. It is difficult to carry out fine prediction of reservoirs based on conventional inversion methods, which in turn affects the development plan and adjustment plan of the oilfield. implement. [0003] Geostatistical inversion technology is a common method for high-resolution reservoir prediction at present. Its principle is to use known seismic information, logging information, and geological inf...

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Problems solved by technology

However, at present, there are relatively few studies on the construction of stratigraphic grids. In actual work, key parameters such as vertical and horizontal ranges and lithological distribution trends in inversion are often selected based on experience and parameter testing, resulting in low parameter accuracy. , lack of geological meaning

The offshore well pattern is sparse, and the braided river delta sedimentary reservoirs vary greatly vertically and horizontally. It is difficult to perform inversion based on the inversion parameters obtained by existing methods to meet the needs of fine reservoir prediction.

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