Contrast method for single sand body inside composite sand body of offshore oilfield

Abstract

The invention discloses a contrast method for a single sand body inside a composite sand body of an offshore oilfield. The contrast method comprises the following steps of measuring a section of a transection sedimentary body of the cross-well composite sand body of the offshore oilfield in a long-axis direction to obtain a backbone section of the composite sand body; aiming at the selected backbone section, selecting gyration flooding surface mud rock top face in the middle period or short period of the composite sand body to obtain an isochronal interface with the leveled flooding surface mud rock top face; leveling the isochronal interface, and dividing the vertical development phases of the composite sand body on the interface according to earthquake, logging and well data of a measured single well; on the basis of the divided development phases, recognizing lateral boundaries of the cross-well composite sand body according to the sensitive earthquake attributes; analyzing the interior structure of the composite sand body according to the vertical development phases and the lateral boundaries of the composite sand body to obtain contrast of the single sand body inside the composite sand body. According to the contrast method, the structural relation inside the sand body can be given; the relation of the cross-well sand body is accurately described through the further utilization of the offshore oilfield earthquake data.

Description

technical field [0001] The invention relates to a method for comparing a single sand body inside a composite sand body in an offshore oil field, and belongs to the field of oil and gas field development. Background technique [0002] At present, in the process of exploration and development of oil fields, it often occurs that the oil production wells close to the water injection wells are not effective, while the oil production wells farther away from the water injection wells have better connectivity. It is found through research that most of the laterally stable distributed sand bodies are actually stable distributed composite sand bodies. Composite sand bodies are formed during the sedimentary evolution of rivers and deltas. Due to changes in the base level, terrain gradient, and hydrodynamic conditions, the channels and sand bars continue to migrate and swing vertically and laterally. form. Composite sand bodies are formed by splicing and superimposing multiple single ...

AI Technical Summary

Problems solved by technology

There are three problems in the traditional sand body correlation: ①The sand bodies in the same sublayer or unit are all connected, which does not reflect the sedimentary origin and internal structural relationship

③ The timeliness of sand bodies between wells needs to be verified

The traditional comparison method can only show the spatial distribution of sand bodies, and it is difficult to reflect the sand body level, so as to realize reservoir prediction and evaluation

Its fundamental limitation is that this method cannot solve the heterogeneity problem inside the reservoir, and analyze the internal structure, connectivity and injection-production effect relationship of the reservoir sand body. Therefore, in the later stage of offshore oilfield development, this method The drawn maps are not convenient for application and practice

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