| 3D geological model is a digital model that reflects geological changes and distributions in three dimensions.The building of a quantitative geological model that can correctly reflect geological features and scales of reservoirs is the core and purpose of modern reservoir description,and it is the key to carrying on good reservoir simulation and dynamic prediction, And it is also the basis of forming a real and objective understanding towards reservoirs and developing them with high efficiency.At the same time,3D geological modeling is a technological issue that is faced by reservoir geologists,as it can characterize reservoir features quantitively,and it can portray reservoir heterogeneities of various scales as well. The basis of oilfield development production and research work lies in3D geological modeling of reservoirs. Therefore,3D geological modeling of reservoirs is the key and core of geological research,and it also the final outcomes of reservoir characterization. Reservoir3D geological modeling comprizes all kinds of contents and every aspect of reservoir geological researches, and it is also the bridge that connects various disciplines,such as geology,seismology,logging and petroleum reservoir. Thus,the success of3D geological modeling of great significance in making development strategies,forecasting development indexes and determining the success of development plans. Reservoir3D geological modeling is characterized by intuition and visualization,thus, it can help us develop a deeper understanding towards reservoir features,and it contributes to the high-efficient development and management of reservoirs.Its precision directly determines and influences the reasonableness of development well designs,consequently the establishment of3D geological models has become the trend of reservoir development.Subsurface reservoirs have certain properties and characteristics in nature. However,due to the incomplete information,there will be some uncertain factors in people’s understanding towards reservoirs,and it is hard to grasp the real characteristics of reservoirs in different scale,thus,reservoirs are supposed to have randomness.The purpose of reservoir modeling is to further describe reservoir lithology,distribution and development features of porosity, permeability and saturation within the structural model framework,and to develop a fine characterization of heterogeneities within reservoirs and its internal properties in three dimensions.Reservoir modeling provides the original geological model for numerical simulation and fine description of residual oil.Reservoir3D geological modeling is mainly divided into two parts, structure modeling and property modeling,and structure modeling is the foundation of all work. Structure modeling is a key step in reservoir modeling,and modeling plans should be flexibly developed according to the structural characteristics of geobodies in the studied area. During the modeling process,in order to construct a reliable model,necessary modifications,such as controlling points adding,fault lines editing and abnormal points correcting,should be carried out under the guidance of rich geological experience.On the foundation of the established structural model,inner boundary which is modeled on fault plane is performed formation block division,and according to the occurrence of strata, geological model which takes3D grid as the basic unit is generated,and it is called3D layered entity model. Subsequently,on the basis of entity model,the building of petrophysical properties model with the application of Krigging estimate and random simulation is called property modeling.This model mainly adopted Petrel software. During the modeling,the integration of special techniques of3D modeling softwares and basic geological researches plays an important role in basic geological researches,such as fine structure location and fine stratigraphic correlation,and problems that are difficult to deal with through conventional means have been solved,and model precision has been guaranteed as well.The paper mainly introduces the concept of reservoir modeling;it summarizes different modeling methods and its basic steps; it compares the differences between deterministic modeling and stochastic modeling; it also carries out a key research on3D structural modeling, which is vital for later property modeling. Deterministic modeling is more applicable in blocks that have dense well pattern, abundant materials and uniform reservoir structures; Whereas,in blocks which have incomplete materials, complex spacial disposition of reservoir structures and spacial variation of reservoir parameters,in order to balance errors and improve precision of models,stochastic modeling are the most favorable. In other words,stochastic modeling has more advantages in the study on reservoir heterogeneities,and it is more suitable for the practical conditions of the studied area. Therefore,stochastic modeling occupies a higher weight in this modeling process.The paper makes a detailed analysis on the structural characteristics of buried hills,and it studies faults development within buried hill reservoirs of Xinglongtai. On the basis of existing materials,such as seismic,drilling,logging and analysis information,researchers conducted3D structural modeling on its faults and established fine3D strata skeleton model,which lay a solid foundation for later researches.This paper mainly introduces basic ideas,workflow,technical requirements,and problems frequently encountered in buried hill reservoir geological modeling. By taking Xinglongtai Buried Hills as the object of study and applying geological modeling software Petrel,comprehensive geological research was carried out through the establishment of fine3D geological model,and by utilizing manual intervention and3D visualization interactive editing,the structural model of this burial hill was finally realized. Through this research,main achievements are as follows:1. Researchers developed a deeper understanding on present conditions and future trends of3D geological modeling and its related softwares around the globe. Trough detailed researches on the concepts of3D geological modeling and its two different methods,namely deterministic modeling and stochastic modeling,knowledge on these aspects have also been gained.2. Through3D geological modeling,reservoir geology knowledge base has been constructed,and integration and standardized processing of basic data have been accompli shed, such as seismic database, strata division database logging database, lithic facies database and reservoir properties database.3. The analysis of structural characteristics of burial hill reservoirs of Xinglongtai lay a solid foundation for later3D structural modeling.4. With the application of structural horizons and fault data derived from seismic interpretation,and with the restraint of single well model,fault model and stratigraphic framework model were established,which are faithful to original basic data.5. On the basis of comprehensive geological researches,by utilizing fault and horizon data derived from seismic interpretation and applying3D structural model generated by Petrel,according to reservoir characteristics and numerical simulation requirements,grid systems were set up to meet the demands of reservoir numerical simulation. It provides data bodies of3D geological model for numerical simulation.This paper focuses on3D structural modeling,and based on the structural characteristics of Xinglongtai Burial Hills,it comprizes theories and methods of various disciplines,including sedimentary,sequence stratigraphy,petroleum geology,reservoir engineering et al.. On the foundation of basic geological researches,with the application of advanced reservoir modeling,fine structural model of this area was constructed,It reflects the subsurface geological conditions objectively,authentically and accurately, and it also reveals the concentration rules of petroleum,which lay a solid foundation for developing the reservoirs efficiently and reasonably. |
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