Guizhou Chishui Area Two, The Structural Analysis Of The Triassic Reservoir And Fracture Prediction Research

The exploration and development of fracture reservoir is a world-class hard work. Chishui area locates in the south edge of Sichuan basin .The reservoirs of this area mainly lays for yan-gxin tong of the Permian System and jialingjiang ,leikoupo of the Triassic System .These three reservoirs are all typical model of fracture- hole pattern.The accumulation of the Chishui area are plentiful, just for the natural gas there will be 2 X 10~11 cubic meter. But, since the understanding of the structure formulation and evolvement is unclear, and the understanding of the fracture growth and distribution is unclear either, the exploration of reservoir still fall behind. Therefore, this paper will mainly describe the form of structure and the history of the evolvement, and study the reason of structure form and the force source. At the same time, by the two-dimension numerical simulation of the palaeostructural stress field in the Chishui area, it tries to rehabilitate the palaeostruc- tural stress. And by combining the basic theory of the structure geology and rock mechanics, it intends to study the character of the rock breakage and the growth distribution of fracture.Main research results:1) After the research of the fracture system from several aspects, it clearly suggests that" the latitudinally-trending structures were formed early while the meridional structures late, in the period that the meridional structures formed it urge the other structures to move and create activation".2) To the source of force of the two structures systems, especially study the great environment of the eastern region structure associated with the force source about the nearly south-northern direction structure .we suggested that the meridional structures and the east structures of Sichuan form at the same time, and that the asymmetry distribution of the structure force in the southeastern edge of Sichuan basin , that the stress direction move to south continuously.3) Make use of the method of two-dimension , simulation compute the fracture stress field of the yangding Lljl and leikoupo at different time , recovered the old fracture stress field .4) According to the character of the old structure stress field, associated with the feature of rock mechanics-, calculate the degree of the rock breakage, and predicate the growth and distribution fracture .5) According to the character of the degree of rock breakage, analyse and predict the distribution of the fracture in three reservoirs.Above research results through the spot operation prove that the method of study is dependable, function strong, to the research and development of the fracture reservoir it has wide-spread meaning and operability.