Application of ColchisFM in the Study of Typical Hydrocarbon Reservoirs in the Bozi Area, Kuqa Depression
Colchis PetroConsulting
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Many professionals may wonder: how can one generate a seismic forward modeling profile using only a single cross-sectional image? This can be especially challenging in geologically complex areas where structural relationships are intricate. However, the process is actually quite simple.
To explore this, we take a typical hydrocarbon reservoir profile from the Bozi area in the Kuqa Depression as an example.
Background
The Bozi-Dabei area of the Kuqa Depression in the Tarim Basin is located in the western part of the Kelasu structural belt. Its hydrocarbon source rocks are mainly distributed in the Jurassic and Triassic formations. The oil and gas-bearing formations in this area consist of tight sandstone reservoirs in the Lower Cretaceous Bashijiqike Formation. These reservoirs are highly heterogeneous and buried at depths of 6,000–8,000 m, making them a primary focus of deep to ultra-deep hydrocarbon exploration in recent years. The area is characterized by strong structural deformation, a complex fault system, and densely distributed structural traps.
Using ColchisFM software, a model was built based on a typical hydrocarbon reservoir profile of the Bozi area. Forward modeling was then performed to characterize the structural and depositional features of the area through seismic reflection characteristics. The specific workflow is as follows:
1. Digitalizing the Typical Hydrocarbon Reservoir Profile of the Bozi Area
The profile image (Figure 1) is directly imported into ColchisFM for digitalization. This image serves as a base map for interpreting horizons and faults. The software then enables one-click model framework construction and stratigraphic assembly, as illustrated in Figure 2.
2. Hybrid Modeling Using Well Interpolation and Manual Parameter Assignment
If well log data is available, well interpolation can be used. In addition, geological bodies can be assigned reservoir parameters flexibly. Well interpolation must be conducted in the depth domain, and ColchisFM offers multiple methods for time-depth conversion. In this case, a constant velocity of 4,000 m/s was used for direct depth conversion. A velocity log was then imported, and well interpolation was used to generate the velocity property profile.
It is important to note that well logs must cover the corresponding stratigraphic depth; otherwise, manual parameter assignment is required (Figure 3). When multiple wells are available, multi-well interpolation is recommended. The more well data incorporated, the more refined the model becomes, leading to higher accuracy and better comparability of the forward modeling results.
3. Forward Modeling Results
The figure below presents a comparison of the depth-domain model, the post-stack forward modeling result, and the pre-stack forward modeling result in the time domain for the typical hydrocarbon reservoir in the Bozi area.
ColchisFM enables rapid post-stack and pre-stack forward modeling, as well as fluid substitution modeling. This allows for the simulation of seismic reflection characteristics under different reservoir conditions, helping to analyze the seismic response of oil, gas, and water saturation variations.
Reference
Yang Haijun, Shi Wanzhong, Du Hao, Shi Lingling, Wang Xiang, Dong Guoning, Mo Tao, Zuo Tingna, Xu Litao, Jiang Xiaojun. Hydrocarbon Charging Phases, Maturity, and Their Indications for Structural Trap Formation Timing in the Bozi-Dabei Area, Kuqa Depression. Acta Petrolei Sinica, 2024, 45(10): 1480-1491.