A Layered Interpretation Method for Carbonate Buried Hill Caves

Abstract

The invention discloses a stratification interpretation method for caves in buried hills of carbonate rocks, belonging to the fields of geology and petroleum development. The present invention, on the basis of considering the geomorphological characteristics of carbonate reservoirs and the formation of caves, divides the single well caves according to the drainage datum, realizes tracking on the leveling seismic data, and finally finds the distribution law of high-efficiency wells, improving the efficiency of wells. The accuracy and success rate of the location are beneficial to the analysis and prediction of the connectivity between wells and the deployment of the well location. It is suitable for the mid-to-late stage development of petroleum in carbonate rock areas with complex landforms and multiple tectonic movements.

Description

technical field [0001] The invention belongs to the field of geology and petroleum development, and in particular relates to a layered explanation method for caves in buried hills of carbonate rocks. Background technique [0002] In the petroleum exploration and development industry, the rocks or rock layers with certain interconnected voids that can store fluids and infiltrate them are called reservoirs or reservoirs. Carbonate rock reservoirs are divided into three types: vugs, caves and fractures. Karst karst areas have been exposed and eroded for a long time, and the surface reservoirs are mainly vugs and caves. In the process of petroleum exploration and development, accurate prediction and identification of reservoirs has become a necessary technical means for the deployment of exploration wells, evaluation wells and development wells. Therefore, establishing an accurate reservoir prediction and identification method is a very critical issue. [0003] At present, the ...

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Problems solved by technology

[0008] In the process of realizing the present invention, the inventors have found that the existing seismic attribute method predicts the reservoir at least the following problems: 1. It is not suitable for the development of the oil field in the middle and later stages: when the oil field enters the middle and later stages of development, it is more and more difficult to find large-scale karst caves. It is mainly to find small caves and holes, but the seismic response characteristics of these reservoirs are not very obvious, so it is not easy to choose the threshold for defining reservoirs in terms of seismic attributes; Impact: The seismic attribute method simply believes that as long as the reservoirs developed within 20ms below the surface of the buried hill have oil and gas distribution, but in the karst karst development area, the residual hills and valleys criss-cross and the terrain is complex. Prediction of reservoirs is not conducive to the discovery of reservoirs, and is also not conducive to reservoir evaluation and target selection; ③ The influence of cave genesis is not considered: in buried hill karst areas, the development of cave systems is mainly affected by underflow surfaces, lithology and fracture systems. control

However, when the seismic attribute method is used for reservoir prediction, the cause of cave formation is not considered. Therefore, in the middle and late stages of oil development, the connectivity analysis of caves cannot be guided. The scale of caves is getting smaller and smaller, the structure of fractured-vuggy bodies is becoming more and more complex, and the range of reservoirs controlled by a single well is difficult to grasp. Therefore, the risk of connecting newly deployed wells with old wells is increasing. Reservoir Prediction and Identification Method

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