Loose sandstone gas reservoir boundary determination method and device

Abstract

The invention discloses a loose sandstone gas reservoir boundary determination method and device. The loose sandstone gas reservoir boundary determination method includes that determining a stacked section and unstacked shot gather data according to seismic data of a work area to be determined; determining a target layer of an abnormal gas containing area and a transverse gas reservoir range of the target layer of the abnormal gas containing area according to the stacked section; picking up the determination time correction amount for the target layer of the abnormal gas containing area; using the time correction amount for the unstacked shot gather data in a common mid-point gather low-frequency mode to perform time division window time difference correction, and generating the seismic data of a horizontal layer-shaped stratum; determining an offset distance range according to the transverse gas reservoir range; generating positive and negative offset distance speed fields according to the offset distance range and the seismic data of the horizontal layer-shaped stratum; subtracting the speeds of the sample points on the spaces of the positive and negative offset distance speed fields to generate a speed difference field; determining a gas reservoir boundary according to the speed difference field.

Description

technical field [0001] The invention relates to oil and gas geophysical prospecting technology, in particular to a method and device for determining boundaries of unconsolidated sandstone gas reservoirs. Background technique [0002] In recent years, global energy consumption has been committed to changing the energy structure. Natural gas, a clean energy, will play a leading role in the global low-carbon development process. China's first 12th Five-Year Plan for natural gas has also been released. This is the energy form of natural gas. The first national-level planning of China made natural gas exploration a hot spot in seismic exploration. With the development of seismic exploration in areas with complex geological conditions, natural gas exploration is also developing in the direction of fine exploration, and it is necessary to develop targeted technologies for different underground geological lithologies and gas reservoir types. [0003] The discovered natural gas rese...

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Problems solved by technology

At present, the mature velocity analysis method is carried out on the gathers of the common central domain. According to whether the dynamic correction can level the reflection time-distance curve and whether the stacking energy can be enhanced as the criterion, this technology is common in stacking imaging in all seismic data processing. With the technology adopted, for the "gas chimney" phenomenon after the unconsolidated sandstone is gas-bearing, the boundary of the gas reservoir may appear in the same common center point gather, but the boundary range cannot be specifically determined

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