Facies-controlled Modeling Research Articles

A Modeling Approach for Beach-Bar Sand Reservoirs Based on Depositional Mode and Sandbody Volume

Beach-bar sand in lacustrine facies represents one of the most significant reservoirs. Depending on the depositional characteristics, it can be further divided into two different sedimentary microfacies, beach sand and the bar sand. Favorable reservoirs are often developed in bar sand. The lower section of the upper part of the 4th member of the Shahejie Formation in the Gao89-1 block is a typical nearshore shallow water beach-bar deposit. Oil distribution is influenced by lithofacies and physical properties. In order to better characterize the heterogeneity within beach-bar sandbodies, a modeling method based on the depositional mode and sandbody volume is proposed. Firstly, a sandbody model is established. On this basis, an algorithm for distinguishing between beach and bar sand based on vertical thickness is proposed. The model is post processed based on the sandbody volume to remove unreasonable sandbodies. The method allows for a more realistic three-dimensional geological model of the beach-bar sands in the study area than the classical two-point geostatistical, object-based, and multi-point simulation method. A facies-controlled modeling approach is used to establish a petrophysical property model on this foundation; the result shows that the property models better reflect the characteristics of the petrophysical distribution in the Gao89-1 block.

3D Quantitative Prediction of the Groundwater Potential Area-A Case Study of a Simple Geological Structure Aquifer.

The Ordos Basin is a sedimentary basin located in Inner Mongolia, China, where coal and uranium coexist. Water inrush disasters have always been one of the main disasters that threaten the safety of coal mine production, and thus, the study and division of groundwater potential regions are of great significance for the prevention of water inrush disasters and in situ leaching of sandstone-type uranium ore. A new method combining truncated Gaussian simulation and sedimentary facies control was established to predict the groundwater potential area. Taking a typical aquifer, the Zhiluo Formation, as an example, based on high-resolution sequence stratigraphy, geophysics, sedimentary geology, and geostatistical theory, the plane distribution of sand bodies was predicted. Furthermore, the relationship between rock porosity and electricity porosity was established to calculate the regional porosity. Combined with truncated Gaussian simulation and facies-controlled modeling methods, a facies-controlled heterogeneous property model was established to analyze the heterogeneous effective porosity of the aquifer in the study area. Groundwater potential areas were quantitatively evaluated by 3D modeling analysis. The results of the evaluated model were verified by actual data and provide a geological guarantee for the accurate mining of deep coal and uranium ore. A 3D distributed model of chemical elements, which is meaningful for in situ leaching uranium mining, is expected in future research.

Facies-Controlled Modeling for Permeability of Tight Gas Reservoir Based on Hydrodynamic and Geophysics Characteristics

Due to poor physical properties and strong heterogeneity of Daniudi tight gasfield (China), traditional methods are not ideal for predicting reservoir permeability. Based on geoscience data mining algorithms and modeling techniques, this parameter is predicted and characterized from a new perspective. The high precision hydraulic unit information was outputted by the BP neural network and the interwell database was predicted by sequential indicator simulation based on the logging and core data, the exponential and power law relationship functions were selected to participate in the construction of the permeability model. The results showed that the facies-controlled modeling system for permeability based on the hydrodynamic characteristics of tight gas reservoirs could effectively improve the accuracy of reservoir prediction, and the logging information in the longitudinal direction and the facies information in the plane were combined by the hydraulic unit.

Research on Modeling Approach of Interlayer in T5 Oilfield

The interlayer plays an important role in the distribution law of remaining oil in the process of oilfield development, and it is of great significance to the later study of remaining oil distribution and the adjustment of oilfield development plans. Synthesize logging data, seismic data, and layering data of T5 oilfield, adopt the interlayer as the structural unit to build 3D model of the interlayer, which effectively reveals the distribution law of the interlayer. On the basis of this model, the facies-controlled modeling technology is used to build the attribute model, and lays a solid foundation for subsequent reservoir research work.

Description and Understanding of Complex Fault Block Reservoir Geology

Reservoir description is an important step in oilfield development. Before mining, using various technical means to analyze and study oilfield structure can achieve the purpose of fully understanding the reservoir and provide theoretical basis for reservoir development. In this exploration, the background of description of complex fault block reservoir geology is analyzed, and X35 reservoir is selected as the research object to study the regional geological reservoir. By analyzing the fault distribution characteristics of X35 reservoir, the reservoir strata are divided. The three-dimensional (3D) geological model of the reservoir is established by using the method of facies-controlled modeling and numerical simulation. Finally, the 3D geological model is tested. The results show that the model has high accuracy and reflects the distribution of X35 reservoir, which has a certain guiding significance for the exploration and effective development of the remaining oil in the reservoirs distributed in this area.

Sedimentary characteristics and seismic geomorphology of the upper third member of Eocene Dongying Formation in double slope systems of Laoyemiao transverse anticline, Nanpu Sag, Bohai Bay Basin, China

Abstract The upper third member of Eocene Dongying Formation (Ed3u) is considered to be one of the most important hydrocarbon-rich intervals in Nanpu Sag, Bohai Bay Basin, China. Through integrated analysis of the drilling cores, wire-line logs, and high-quality three-dimensional (3-D) seismic data, the sedimentary characteristics of Ed3u were analyzed by utilizing the seismic geomorphology approach in the double slope systems of Laoyemiao transverse anticline, Nanpu Sag. The Ed3u, a third-order sequence, can be subdivided into three fourth-order sequences (from base to top as SS1, SS2, and SS3). The fan delta front and sublacustrine fan have been identified from well-based analysis of the sedimentary facies and core examinations reveal that the sublacustrine fan deposits were dominated by six types of resedimented lithofacies, namely, slides, slumps, sandy debris flows, muddy debris flows, turbidity currents, and hyperpycnal flows. Stratal slices were obtained from 3-D single-frequency seismic volumes to map the sediment dispersal characteristics and document the evolution of the depositional systems constrained by the double slope break zones of Laoyemiao transverse anticline. The unique structures of the double slope break zones and the variation in the lake level associated with the system tracts of the third-order sequence jointly control the dispersal patterns of the sand bodies and the spatial-temporal evolution of the depositional systems. Based on the above analysis, the depositional evolution model of Ed3u was established. The proposed facies-controlled model and sediment transport model can be used to accurately predict the favorable reservoir sandstones.

Study on facies-controlled model of a reservoir in Xijiang 24-3 oilfield in the Northern Pearl River Mouth Basin

To better understand the internal structure of the Xijiang 24-3 Oilfield in the Northern Pearl River Mouth Basin, a reasonable and effective three-dimensional quantitative geological model is needed to characterize the distribution characteristics of the reservoir. Xijiang 24-3 Oilfield is a braided river delta deposition, which contains many sedimentary microfacies in three subfacies zones. The reservoir structure is complex and heterogeneous. The reservoir modeling research was conducted on the Xijiang 24-3 oilfield H3A reservoir. Analysis of the oilfield core, the well-logging, and seismic data, establish a regional structural model. The regional sedimentary microfacies model is simulated by multi-point geostatistics. The reservoir property model is established by using facies-controlled modeling technology with sedimentary microfacies as a constraint condition. A facies-controlled property model and a non-facies-controlled property model are established respectively. The facies-controlled model corresponds well with the sedimentary microfacies of the reservoir, and the variation trend of the model shows a higher coincidence rate with the distribution characteristics of the well. The facies-controlled model reflects the spatial distribution characteristics of the physical properties of the underground reservoir and is in accord with the actual geological understanding of the reservoir. This model also provides a reliable basis for the next stage of reservoir description and a basis for further exploration and development work. Cited as : Zheng, L., Chen, C., Lu, C., Cheng, M. Study on facies-controlled model of a reservoir in Xijiang 24-3 oilfield in the Northern Pearl River Mouth Basin. Advances in Geo-Energy Research, 2018, 2(3): 282-291, doi: 10.26804/ager.2018.03.06.

Geostatistical modeling for fine reservoir description of Wei2 block of Weicheng oilfield, Dongpu depression, China

The Wei2 block of Weicheng oilfield is characterized by complicated structure mainly caused by high degree of fault development. Multiple reservoir types are found in this block and the reservoir heterogeneity is severe. The oil and gas reservoirs have already stepped into the stagnant stage of a great water-cut degree together with a rapid production decline rate. Thereby, both stabilizing the oil and gas production and optimizing adjustment for further exploitation make it urgent for geomodelers to build a useful model to predict the inter-well parameters and the distribution of the remaining oil and gas. A three-dimensional geological model established with the help of stochastic modeling technique may provide a perfect window and carrier for fine structure interpretation and reservoir heterogeneity description, compared with a traditional two-dimensional model. Hence, based on stratigraphical layering points, significant surfaces and fault points as well seismic interpretation, an integrated structure model is developed. Using the truncated Gaussian simulation and taking the existing geological maps as references, the sedimentary microfacies model was successfully constructed. Through the use of sequential Gaussian simulation method and the facies-controlled modeling method, the reservoir physical properties are populated. Meanwhile, the comparison between facies-controlled and non-facies-controlled property models indicates that the former is more loyal to previous researching and the representation of heterogeneity is ideal. Finally, the ideas of sample density and reserves fitting are proposed to evaluate the practicability and accuracy of the property models.

Application of Facies-Controlled Physical Property Modeling in Oubei Block, Jinhu Depression

Three dimensional (3D) models provide insights into the distribution, external and internal geometry of the reservoirs. The core description shows that the fourth segment of Funing Formation (E1f4), Oubei Block, Jinhu Depression mainly develop delta front subfacies which included underwater distributary channel, mouth bar, sand sheet and so on. Well data and structural maps were integrated to build 3D structure model and sedimentary microfacies model of Oubei reservoirs using stochastic simulations with geometry data. The result of facies-controlled property model can reasonably reflect reservoir characteristics in detail, providing a reliable geological model for late reservoir adjustment and valuable reference for numerical reservoir simulation as well.

Application of Facies-Controlled Modeling in Physical Property Modeling – A Case of Tuo 128 Block

The foundation and core of the phased modeling non-homogeneous modeling, Shengtuo oilfield geological modeling of the low porosity and permeability reservoir description of the characteristics of data is small, the accuracy is low, uncertainty factors. Using phased stochastic modeling techniques, log interpretation, based on data combined with core analysis, production performance and other known information, the sedimentary facies model as constraints holes, seepage property modeling to reduce the reservoir description is not uncertainty, combined with sequential Gaussian simulation method to establish a geological model of the actual production status of the oil region, the geological basis for the block rational development decisions and improve the effect of oilfield development.

Application of facies-controlled modeling technology to the fault-block A11 in A'Nan Oilfield

Abstract The fault-block A11 in the A'Nan Oilfield of the Erlian basin is now at a high water-cut period, and its reservoir heterogeneity has severely affected development results. To accurately describe the reservoir and its through-going characteristics, this article establishes a structural model, a sedimentary microfacies model, and a microfacies-controlled petrophysical model, step by step, using facies-controlled modeling technology with multiple stochastic modeling methods and on the basis of study results on seism, logging, geology, and development performance. The correlation of analogy results between facies-controlled petrophysical parameters and direct petrophysical parameters reveals that the facies-controlled attribute model is more reliable in describing reservoir heterogeneity. The successful application in the A'Nan Oilfield shows that facies-controlled modeling technology can satisfactorily realize the petrophysical parameter analogy of reservoirs with quick-change sedimentary microfacies and severe heterogeneity, providing a dependable geological basis for the later development and adjustment of oil and gas fields.