Font Size: a A A

The Kalagang Of Niudong Block In Santanghu Basin Comprehensive Evaluation Of The Volcanic Reservoir

Posted on:2013-04-03Degree:MasterType:Thesis
Country:ChinaCandidate:J Y FengFull Text:PDF
GTID:2230330374976796Subject:Geological Engineering
Abstract/Summary:PDF Full Text Request
With the increasing demand of hydrocarbon resources and the difficulty in exploration and development worldwide, the domestic and international exploration indicates that igneous rock has great potential of being good reservoirs. Volcanic rocks, as a special type of reservoirs, are attracting more and more people’s attention, however, the discovery and exploitation of the volcanic reservoirs is not well developed, and the overall research degree is relatively low. Volcanic logging evaluation is a new discovered important area of research after the sedimentary and carbonate reservoir logging evaluation has been placed great emphasis on. There are three main difficult points of the volcanic rocks reservoir logging evaluation. The heterogeneity of the reservoir comes first. Controlled by multiple factors of distribution and physical properties of the volcanic reservoirs, coupled by development of fractures, the conditions of igneous reservoir becomes more complicated. As a result, the volcanic reservoir geological modeling has become extremely complex. Based solely on the homogeneous reservoir, it is difficult to quantitatively calculate the parameters of reservoir porosity, permeability, saturation, etc. Secondly, igneous rock reservoirs are controlled by structure, hydrocarbon mother rock, etc. It significantly reduces the volcanic lateral continuity. Thirdly, it is very difficult to define the pore configuration, fracture width and development degree by using conventional logging techniques.This paper describes the characteristics of volcanic reservoir in its reservoir space types, type of combination, pore structure evolution, etc. There are three major types of reservoir. They are volcanic cracks reservoir, volcanic crack-pore type reservoir and volcanic crack-dissolution porosity reservoir. This paper also introduces fracture complex reservoir geological characteristics, including Cracks in the definition, classification, characteristics of cracks and the cracks in the identification of FMI. Also, the impact of the volcanic reservoir properties in the work area is explained in detail. On the basis of analyzing geological and geophysical characteristics of fractured reservoir, the interpretation and evaluation of the fractured reservoir, which combine the conventional logging data and FMI, has established.. In this manner, the Kalagang formation of block niudong in Santanghu basin volcanic reservoir could be interpreted. The contrast and evaluation of volcanic section and flat can be made.According to the genetic classification, fracture system can be divided into shear cracks, expansion cracks and tension cracks. In addition to the classification based on width and occurrence, the fracture system also can be divided into structural fracture, regional cracks and shrinkage cracks according to its mechanical properties. In the fracture system, the main nature of cracks that impacts the reservoir performance is fracture morphology. Whether or not the cracks are open, deformed, or mineral filled, these properties all have a direct impact on the oil reservoir. Cracks have some special reflection on the resistivity logging, acoustic logging, density logging and natural gamma logging. This special reflection enables logging to evaluate the interpretation of the fractured reservoir. Interpretations of the reservoir used in interpreting model in the past are homogeneous model.In recent years imaging logging data (FMI) are applied in the volcanic oil-gas exploration in the area, and provide a reliable basis for Recognizing the volcanic rocks and the characteristics of fractures in volcanic rocks. Based on analysis of imaging logging data of volcanic rocks in the area, it is concluded that the major lithologic include tuif,bedded tuif, volcanic breccia and basalt; and there exist five types of tectonic fractures in volcanic rocks, such as vertical fractures, high-angle fractures, oblique fractures, horizontal fractures an d reticulate fractures.Volcanic cracks in the reservoir layer have severe heterogeneity than that in ordinary homogeneous formation. According to this characteristic of volcanic rocks, this paper has done the following research on the Kalagang formation of block niudong in Santanghu basin.①According to the well logging interpretation theory and method, based on the well logging data and core data of the Kalagang formation of block niudong in Santanghu basin, the volcanic rock lithology of the Kalagang formation of block niudong in Santanghu basin has been confirmed. Thus the identification of the lithology can be established to determine the skeleton parameters. The classification of the95wells in the Kalagang formation of block niudong in Santanghu basin based on lithology and lithofacies has completed, and then the percentage of lava thickness of each layer are ensured. Combined well sections and seismic profiles, the rhythmic layers lithofacies plan can be made..②Sub-lithology matrix pore model, fracture porosity model and perm model are created.③Oil saturation equation has been built, and then the calculation of oil saturation according to the equation has done.④According to the above results, the comprehensive evaluation for reservoir has been made to determine oil, gas and water layer.⑤Reservoir interpretation chart is formulated through the establishment of mutual relations of, physical properties, electric properties and oilness of volcanic rocks, then the study of volcanic rock reservoir and oil well logging interpretation method has been established. The lower limit of the volcanic reservoir properties and its classification are determined, and the reservoir effective thickness graphs of9small layers are completed.⑥By using three-dimensional property modeling, sequential gaussian simulation algorithm under phased conditions is established to build porosity and permeability models.Through the phased simulation comparative study of lithofacies logging interpretation and physical properties of rock, the geological condition of the Kalagang formation of block niudong in Santanghu basin is proved true and reliable. This result offers the basis of logging interpretation and proved reserves calculation in niudong well and lays the foundation for the next step of the development of the oil field.
Keywords/Search Tags:Niudong Block, Volcanic reservoir, lithologic identification, Reservoir cutoff, fracture, SanTanghu basin
PDF Full Text Request
Related items