Method for identifying and interpreting carbonate rock ancient karst reservoir layer three-dimensional structure

Abstract

The invention provides a method for identifying and interpreting carbonate rock ancient karst reservoir layer three-dimensional structure. Steps of identifying a single well cave preferably comprise that: according to a cave growing segment with definite rock core and electric imaging well logging information, conventional well logging response characteristics of the cave growing segment are summarized; cave sensitive well logging parameters are preferably selected via a well logging parameter intersection method, and an identification graph plate is established; a multi-parameter normalization weighting method is utilized to establish a cave identification function; steps of identifying an inter-well cave preferably comprise that: a synthetic seismic recording method is utilized toward each single well to calibrate a cave interpreting result of a depth domain to an acoustic inversion data volume of a time domain; then threshold values of a cave segment and a non-cave segment are confirmed so that the inter-well cave is effectively identified; continuous tracking is performed along the middle of caves which are large in scale and great in continuity so that a three-dimensional tracking layer is obtained, an average value of 2ms acoustic save impedance around the tracking layer is computed, and thus a three-dimensional space growing position of an ancient karst reservoir layer is obtained.

Description

technical field [0001] The invention relates to a method for predicting carbonate rock ancient karst reservoir based on well-seismic combination, in particular to a method for identifying and explaining the three-dimensional structure of carbonate rock ancient karst reservoir. Background technique [0002] With the development of my country's petroleum exploration technology, the exploration field has been continuously expanded, and it has developed from conventional clastic rock reservoirs to unconventional reservoirs. Carbonate paleokarst oil and gas reservoirs are one of them. In many oilfields in my country, a variety of carbonate paleokarst oil and gas reservoirs have been discovered one after another. Among them, Tahe Oilfield, which is dominated by paleokarst reservoirs, has become the largest Paleozoic marine oilfield in my country. After undergoing various geological processes such as dissolution, filling, collapse, and burial structure and geochemistry, the format...

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Problems solved by technology

[0004]1. At present, the accuracy of seismic data identification of caves between wells is low, and caves <6m cannot be effectively identified, and the development of caves between wells cannot be effectively clarified;

[0005]2. Paleokarst reservoirs are characterized by strong vertical and horizontal heterogeneity and multi-layer development. Layer reliable 3D structural features;

[0006]3. Due to the inability to clarify the three-dimensional structure of paleokarst reservoirs, the success rate of exploration wells in such reservoirs is low, which seriously restricts the efficient exploration and development of such reservoirs

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