Font Size: a A A

Research And Application Of Fracture Prediction Technology Based On 5D Seismic Gather Data

Posted on:2016-05-08Degree:MasterType:Thesis
Country:ChinaCandidate:X W LiFull Text:PDF
GTID:2180330482476711Subject:Oil and gas engineering
Abstract/Summary:PDF Full Text Request
The unconventional, hidden oil and gas reservoir is becoming the exploration focus. The lower Paleozoic Ordovician carbonate rocks in the Tarim Basin is the main battlefield of production construction of" Xinjiang Daqing". Currently, Haven found a number of large oil and gas fields in Tabei, Tazhong, Hetian areas, the equivalent of third class reserves nearly 18 million tons. The geological characteristics of carbonate reservoir, which is characterized by three aspects: ① Deep buried;② The reservoir has strong heterogeneity, the holes are connected by the cracks;③The gas, oil and water distribution characteristics are complicate, there is a huge difference in the accumulation of oil and gas in different reservoir space, exploration and development are difficult. Over the years, through exploration and development research, it has become clear that:fracture prediction and hydrocarbon detection in the exploration and development of carbonate rock is very important, crack quantitative research has important practical significance. In recent years, with the promotion of the " Wide azimuth, broadband, high density " technology, Through the research of OVT domain processing technology, it has been obtained that the data of the 5D gathers is better, which is more conducive to the prediction of fracture. Based on the interpretation of 5D gather data, the quantitative study of the crack direction is realized.The study area is located in Tabei and Tazhong, in Tarim Basin, Northwest China. The upper Ordovician stratum develops fractured-vuggy reservoirs, and oil and gas resources are sufficient. It is the main field the oilfield company to increase reserves and enhance the yield. In the integrative practice of exploration and development of deep buried carbonate reservoirs. One of the main challenges is the connectivity prediction and fluid flow direction analysis, making sure the boundary of fractured-cave reservoir (FCR) system. On the basis of full azimuth high density 3D seismic acquisition data, the emphasis of this research is the fractures study, details the distribution and characteristics of deeply buried anisotropic carbonate fracture, and then guides the connectivity study of FCR system.Using five-dimensional (X and Y coordinates, Depth or Time, azimuth and offset) seismic gather data (5D-SGD) to predict fracture is the emphasis of this research. In order to more effectively improve the prediction accuracy of the fracture, systematically analyzed the maximum defect of fracture prediction that using the conventional migration processing seismic data divided into azimuth, that is, the anisotropic reflected by the azimuth migration processing seismic data is not the real anisotropic of the same reflection point. The application of 5D-SGD is through optimizing offset range, to meet the data imaging conditions, ensure the energy consistency of different azimuth data, at the same time, need to flatten anisotropy on the overlying strata, ensure the authenticity and integrity of amplitude azimuth anisotropy. Therefore, the application of the 5D-SGD to predict fracture has the following advantages: One is flexibility in optimizing offset rang, resolves the contradiction between azimuth partitioning and ellipse fitting principle, ensure the requirements of point number and quality of ellipse fitting data. The next is interactive analysis and quality control with the actual drilling results to improve the reliability of the anisotropy analysis results, realize quantitative study of fractures.Through the effective analysis and application of the 5D-SGD, combined with the actual drilling and logging data, the study projects that using 5D-SGD can effectively improve the accuracy of fracture prediction, can effectively guide the connectivity study of FCR system to deploy efficient well groups in the development block.
Keywords/Search Tags:Carbonate, Fractured-cave reservoir system, OVT gather, HTI media, Fracture quantitative study
PDF Full Text Request
Related items