Practice of High-density 3D Seismic Exploration in Tight Oil Exploration in G Area of Central Sichuan
Tan Rongbiao,
Wang Xiaolan,
Deng Xiaojiang,
Huang Lijuan,
Li Yangjing,
Zhang Ruyue
Issue:
Volume 9, Issue 1, March 2021
Pages:
1-5
Received:
22 November 2020
Accepted:
24 December 2020
Published:
22 January 2021
Abstract: The Oil reservoir in Jurassic of Sichuan Basin is tight, thin, high heterogeneity, complex sand distribution and well-developed micro-fault etc., whose difference of buried depth is up to 2000m from south to north. The vertical and lateral resolution of conventional seismic exploration is too low to predict reservoir clearly, which restrains further development of close oil exploitation in central of Sichuan Basin. Lots of examples shows that high density acquisition is able to improve the description ability of seismic data, In G area of Sichuan Basin, a high-density, high-fold, small-cell, full-azimuthal 3D acquisition has been tested, which is the first mountainous high-density seismic exploration in China. In view of mass data and difficult geological target, a processing technique series including auto-first-break-picking, pre-stack noise suppression, robust surface consistent deconvolution, pre-stack time migration in OVT (Offset Vector Tile) field is applied to obtain high quality image. Analysis of multiple geological target results revealed that, the high-density data has fair higher signal-to-noise ratio, much wider bandwidth with more information, much better vertical and lateral resolution, which increased the identification of sand boundary, predication of thin reservoir, discrimination of micro-fault and fracture, recognition of sub geological features. It is well provided that high-density 3D seismic exploration has vast application future in close oil exploitation.
Abstract: The Oil reservoir in Jurassic of Sichuan Basin is tight, thin, high heterogeneity, complex sand distribution and well-developed micro-fault etc., whose difference of buried depth is up to 2000m from south to north. The vertical and lateral resolution of conventional seismic exploration is too low to predict reservoir clearly, which restrains furthe...
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IFEDC-20194285 Phase-controlled Inversion Under High-resolution Pseudo-impedance Curve
Zhang Ruyue,
Deng Xiaojiang,
Wang Xiaolan,
Tan Rongbiao,
Luo Jing,
Guo Yuchen,
Li Yangjing,
Huang Lijuan,
Li He
Issue:
Volume 9, Issue 1, March 2021
Pages:
6-11
Received:
22 November 2020
Accepted:
25 December 2020
Published:
23 February 2021
Abstract: Currently, conventional seismic inversions are mostly premised on well data, and there exist uncertainty in seismic inversions in areas with few fixed wells. After years of production practice, well-seismic cooperative inversion under the constraint of pseudo wells is a more effective method for reservoir prediction in areas with few fixed wells and complex phase spread changes. Nevertheless, the selection of locations of conventional pseudo wells only takes into account the spatial distribution of wells but seldom considers the changes of phase spreads; curves of pseudo wells are mostly derived from sparse pulse inversion with relatively low longitudinal resolution, which cannot accurately reflect the vertical and horizontal variation characteristics of the reservoir; there is no effective quality control method to prove the reliability of the curve after selecting the pseudo well. To solve the above-mentioned problems, this thesis acquires pseudo-wave impedance curves with high-frequency components by means of waveform difference inversion, controls quality and optimizes the location of pseudo wells under the guidance of geological results, and performs phase control inversion under the constraint of high-frequency pseudo-wave impedance curves, which greatly enhances the vertical and horizontal resolution of inversion, solves the problem of fine reservoir prediction in areas with few fixed wells, and offers strong support for high-speed and efficient development of oil and gas.
Abstract: Currently, conventional seismic inversions are mostly premised on well data, and there exist uncertainty in seismic inversions in areas with few fixed wells. After years of production practice, well-seismic cooperative inversion under the constraint of pseudo wells is a more effective method for reservoir prediction in areas with few fixed wells an...
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