scholarly journals Seismic Wave Field Anomaly Identification of Ultra-Deep Heterogeneous Fractured-Vuggy Reservoirs: A Case Study in Tarim Basin, China

2021 ◽  
Vol 11 (24) ◽  
pp. 11802
Author(s):  
Xiangwen Li ◽  
Jingye Li ◽  
Lei Li ◽  
Zhonghong Wan ◽  
Yonglei Liu ◽  
...  

Ultra-deep (7500–9000 m) Ordovician tight limestone heterogeneous fractured-vuggy reservoir is an important target of FuMan Oilfield in Tarim Basin. The strike-slip fault controlled reservoir is related to formation fracture and dissolution caused by geological stress. The seismic wave-field anomaly characteristics with different energy and irregular waveform are displayed in the seismic profile. Accurate identification of fractured-vuggy reservoirs wrapped in tight limestone is the direct scheme to improve production efficiency. Therefore, a new combination method flow of seismic wave-field anomaly recognition is proposed. In this process, the seismic data must be preprocessed initially, and on this basis, robust formation dip scanning is carried out. Secondly, the dip data is applied to the transverse smoothing filter to obtain the formation background data. Eventually, the seismic wave-field anomaly data is the residual between background data and original seismic data. This method has been applied in blocks with different structural characteristics and can effectively improve the resolution of strike-slip fault controlled reservoirs. Based on the results, the drilling success rate is increased to more than 95%, and the high-yield rate of oil tests is increased to 75% in 2021. Multiple applications indicate that the method is robust and can be popularized.

2020 ◽  
Author(s):  
Debo Ma

<p>Characteristics and evolution process of strike-slip fault is a key issue restricting further exploration in Halahatang area, North Tarim Basin, NW China. This paper uses the new-acquired 3D seismic data and applies fault structural analysis method to study the characteristics of Halahatang area, and discusses evolution process of the faults.<br>The data used in this paper include 1960 km<sup>2</sup> 3D seismic data in prestack time migration in Halahatang area, and 4 wells logging data used to calibrate seismic horizon. The bin size of 3D seismic is 25 m×25 m with sampling rate of 4ms, and data length of 7000 ms. Firstly, the Eigen-structure coherency and SO semblance are used to identify the distribution of the strike-slip fault. Secondly, the segmentation of Ordovician strike-slip fault in the study area is studied and the control effect of segmentation on reservoir development and oil and gas enrichment is discussed.<br>The slip distance of strike-slip fault is very small, the maximum is no more than 2 km. They are typical cratonic strike-slip faults which are developed inside the craton. There are four kinds of structural styles on the profile, which are vertical and steep, positive flower structure, negative flower structure and semi-flower structure. Five structural styles of linear extension, X type, braided structure, horsetail structure, and en-echelon structure are developed on the plane. There are obvious segmentation along the fault trend.<br>According to the strata subjected to strike-slip deformation and the structural styles in different strata, it is determined that the strike-slip faults have three stages of activity in Halahatang area. <br>In the Late Ordovician, NNE, NNW, NE, and NEE strike-slip faults are mainly developed in the study area. The faults on the seismic profile are steep and upright, with small displacements. Faults generally only break into the Ordovician, and later activities will cause faults to go up to the Silurian and even the upper Palaeozoic, which have different tectonic styles with that of the Ordovician faults. The NNE and NNW strike-slip faults form an “X”-type conjugate strike-slip fault, reflecting the conjugate strike-slip fault is generated by near north-south compression.<br>In the Late Permian, 4 NNW transtensional strike-slip faults are generated by the activation of some Ordovician strike-slip faults. In the Late Cretaceous-Palaeocene, the study area mainly develop several groups of NNE, near SN transtensional strike-slip faults. These transtensional strike-slip faults appear as graben and horst or stepped faults on the section. These transtensional strike-slip faults are R-shear faults in the Mesozoic and Cenozoic strata formed by the Ordovician NNE faults slip dextrally under the tectonic stress.</p>


2019 ◽  
Vol 4 (1) ◽  
pp. 141-148
Author(s):  
Sergey Efimov

The article presents a space-time analysis of the seismic wave from a distributed career explosion. The method of direct measurement based on the dynamic model of the wave field is used to form an image of the seismic wave field in the field of quarry explosions. The efficiency of the proposed method is shown by the example of experimental seismic recording processing. The program "Nelumbo" is used to visualize the seismic field, which on the basis of experimental seismic records allows to form an image of the wave field in the space of the hemisphere, the center of which corresponds to the position of the seismometer (registration point). The algorithm of the program "Nelumbo" is based on the Huygens – Fresnel principle and Kirchhoff's theorem. The algorithm of the program allows to allocate from record of a seismic signal frames of a certain duration and to form the image of a wave field in space of a solid angle dimension π. This approach can be used as a tool to analyze the nature of the development of disturbances in the environment and the analysis of environmental risks in the production of blasting.


2020 ◽  
Vol 114 ◽  
pp. 104208
Author(s):  
Guanghui Wu ◽  
Kuanzhi Zhao ◽  
Haizhou Qu ◽  
Nicola Scarselli ◽  
Yintao Zhang ◽  
...  

2020 ◽  
Vol 27 (1) ◽  
pp. petgeo2019-144
Author(s):  
Ziyi Wang ◽  
Zhiqian Gao ◽  
Tailiang Fan ◽  
Hehang Zhang ◽  
Lixin Qi ◽  
...  

The SB1 strike-slip fault zone, which developed in the north of the Shuntuo Low Uplift of the Tarim Basin, plays an essential role in reservoir formation and hydrocarbon accumulation in deep Ordovician carbonate rocks. In this research, through the analysis of high-quality 3D seismic volumes, outcrop, drilling and production data, the hydrocarbon-bearing characteristics of the SB1 fault are systematically studied. The SB1 fault developed sequentially in the Paleozoic and formed as a result of a three-fold evolution: Middle Caledonian (phase III), Late Caledonian–Early Hercynian and Middle–Late Hercynian. Multiple fault activities are beneficial to reservoir development and hydrocarbon filling. In the Middle–Lower Ordovician carbonate strata, linear shear structures without deformation segments, pull-apart structure segments and push-up structure segments alternately developed along the SB1 fault. Pull-apart structure segments are the most favourable areas for oil and gas accumulation. The tight fault core in the centre of the strike-slip fault zone is typically a low-permeability barrier, whilst the damage zones on both sides of the fault core are migration pathways and accumulation traps for hydrocarbons, leading to heterogeneity in the reservoirs controlled by the SB1 fault. This study provides a reference for hydrocarbon exploration and development of similar deep-marine carbonate reservoirs controlled by strike-slip faults in the Tarim Basin and similar ancient hydrocarbon-rich basins.


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