Analysis Of High Grinding Area Of Dengying Formation Four Cave Identification And Evaluation Of The Effectiveness

Since the discovery of Weiyuan gas field in 1964 in Sichuan Basin,a series of exploration has been carried out in order to take the Sinian system as the target layer.11 structures such as Longnusi,Anping Dian and Ziyang have been drilled.In 2011,Gaoshi Sinian Dengying formation gas field was discovered in Sichuan Basin.;The lower Cambrian Longwangmiao gas field was discovered in the Sichuan Basin in 2012-2013.It is revealed that the lower assemblage of Sichuan basin has great prospects for oil and gas exploration.Dengying formation in Gaoshitian-Moxi block as the important exploration target layer in Sichuan area,The main reservoir type after the early tectonic stage and the subsequent multi-stage structural reconstruction is the fracture-cavity reservoir.T development of fractures and cavities in the fourth section of the lamp in the study area is the key to the reservoir prediction research.Fine prediction of seismic reservoir and identification of fractures and cavities are favorable support for development plan formulation and well location deployment.So we need to define the extent of the crack and hole development.Because of the serious heterogeneity in vertical and lateral of fractured and cavernous reservoir.So the conventional logging data are difficult to evaluate.Need to be supplemented with imaging logging and seismic methods.But the existing data for crack detection is not complete.The parameter data of fracture and hole are not obtained completely,so this paper uses the method of combining well and earthquake to identify and detect.An investigation of domestic and foreign literature on the identification and evaluation of fractures and caverns.Then,according to the sedimentary background,stratigraphic profile and tectonic movement of the study area,the analysis was carried out.The reservoir lithology and reservoir space in the study area and the relationship between fractures and caverns are analyzed.The Tongwan movement of two acts provides karst foundation for the development of cracks and cavities in the study area,and the extension of Xingkai fissure promotes the formation of fractures.Combined with the actual situation of reservoir development in the study area,the well logging,geology,drilling and test data of the study area are taken as the basis.Study on reservoir characteristics of fracture and cavity:The response characteristics of conventional and imaging logging and seismic response of fractures and caves are studied.Firstly,the fracture characteristics of conventional logging and the abnormal response characteristics of fracture interpretation parameters are analyzed,and the recognition of fracture-cavity reservoirs is realized.Calculation of poststack seismic coherence attribute and curvature attribute,Identification of fracture and cave development zone by seismic profile analysis;Qualitative Identification of fractures and caverns by conventional and Imaging logging response characteristics for singlewell.Description of fractured reservoir,pore-cavity reservoir and fracture-cave reservoir in the study area.Well logging data are used to evaluate the effectiveness of fractures and caverns.It is necessary to judge true and false fractures and determine the types of fractures by combining with imaging logging to evaluate fractures.Evaluation of filling degree of caves,identification of filling types by FMI imaging logging.Finally,the fracture and cavity body evaluation is carried out in combination with seismic continuous well profile,which shows that the exploration potential of the fourth section of the lamp is great.