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3-D Geostress Field And Migration Of Oil And Gas And Its Application In Liaohe Oil Field Tanhai Area

Posted on:2004-10-28Degree:DoctorType:Dissertation
Country:ChinaCandidate:H C WangFull Text:PDF
GTID:1100360092496459Subject:Geological Engineering
Abstract/Summary:PDF Full Text Request
Petroleum is a kind of strategic resource of great importance. It is meaningful to find out the distribution of oil and gas. The research work done shows that the geostress plays important role on the distribution of oil and gas. Therefore, it is very important to study the field of geostress in oil field. Although much have been done in this aspect, the study is still in the stage of approach because of the complexity of this problem. This dissertation studies numerical modeling of 3-d geostress field, numerical modeling of 3-d fracture and influence of stress and fracture on the migration and accumulation of oil and gas. This dissertation performes an advanced analysis of oil geology, analysis of the history of geostress field in oil field, measuring of tectonic stress, tests of rock mechanics parameters, 3-d FEM (finite element method) numerical simulation for the field of geostress, numerical calculation for three dimensional fracture, analysis of relationship between geostress field and migration of oil and gas, analysis of relationship between fracture and migration of oil and gas, etc. And some great breakthrough has been done. Main outcomes and cognition are given as followings:1. Applying contemporary theory of mechanics, combining analysis of petroleum geological environment with stress-stain analysis of rock, discussing mechanism of migration of oil and gas, this dissertation stresses that the geostress is one of the main driving force for migration of oil and gas. This paper also points out clearly that the average stress is the main driving force for migration of the petroleum in the pore stratum, the downhill direction of average stress gradient is the preponderant direction of the migration oil and gas.2. This paper perfects a whole series of technical routes which begins at research of oil geology, then analysis of rock mechanics, migration theory stress and oil and gas, 3-D FEM mathematical simulation, 3-D fracture simulation, and then integrative analysis of petroleum migration, finally, forecast of target area. It has strengthened the analysis process of three dimensional FEM numerical simulation of geostress field and fracture.3. This paper develops model-building technology of 3-D FEM and establishes a particular set of 3-D meshing and splitting technology. That begins at morphologic description of stratum and fault at first, then forming grid in stratum and then meshing in the 3-d volume structure. The core of which is division technology of 3-d dimensional stratum which is consisted of different kind of rock and contains complicated fault. It can reflect mechanical characteristics of geological model for the field of geostress in the oil field correctly and truly. It has very high efficiency also.4. According to thorough research on mechanical mechanism of 3-D tensional micro-fracture producing, this point is put forward the first time that: there is more stress concentration in the circumference of micro-cracks. And the cracks are easier to expand and to link with each otherwhen the fissures contained saturated pore fluid than dry state. Therefore, it is necessary to modify the Griffith criteria.5. Much research work has been done on improving post-treatment of 3-D FEM numerical simulation. And a software package running in Windows98 system has been compiled which is used for analysis of geostress field in oil field. It can calculate the transform of vector in 3-D space. It can give vector of stress, and break factor and direction vector of tensive crack and shearing crack in the special observation planes (for examples, in a stratal surface which is fluctuant in depth). It can increase the automation in the FEM analysis of 3-D geostress field in oil field. It can realize visualization and automatic map drawing of the results.6. On the basis of theory study, a series of research work has been done in Liaohe oil field Thanhai aera. Some 3-D models has been established which correctly reflectes the true mechnical characteristics and the geometric characteristics...
Keywords/Search Tags:numerical simulation of tectonic stress field, migration of oil and gas, 3-D finite element method, fracture modeling, Liaohe oil filed
PDF Full Text Request
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