Coherent Attribute Strengthening Technology And The Application In The Fine Description Of Low-level Faults

With the further development of petroleum exploration and development,the exploration target has turned to the subtle hydrocarbon reservoirs such as the fault block reservoirs.The distribution and pattern of the shattered fault zones and low level faults play an increasingly important role in fault block reservoir identification and description.Because of the complexity and the small scales of the low level faults,as well as the fuzziness in the breaks seismic of profile event and the variety of the fault combination and the Spatial distribution,therefore,it is difficult to be identified and described by the traditional geophysics methods However,the combination and spatial distribution of low level faults is very important to the further oil field development.Therefore,it has very important theoretical significance and practical value to systematically researching the identification and description technology of the shattered fault zones and low level faults.Through the investigation of references at home and abroad,this paper introduces the present status of the coherent technology in the Interpretation of low level faults.Combined with the characteristics of low level faults,the method of seismic conventional attributes analysis and the curvature attribute analysis are used to study the practical effect of the working area.Then,a detailed Formula derivation process and practical application of the method of three-generation coherent technologies are introduced.Through comparative analysis,the advantages and disadvantages as well as the limitation in low level faults interpretation of the three-generation coherence technology are found.Due to the improvement of the requirements in underground geological structure fine explanation,the traditional coherent algorithm is not enough to meet the requirement Therefore,it is necessary to study the methods to strengthen the coherence technology.In this paper,four kinds of methods to strengthen the coherence properties are introduced,meanwhile these methods are used in the low level faults detection to check the practical effect in real seismic data.The method based on wavelet frequency division coherent attribute and attribute fusion RGB display technology,makes these different frequency bands coherent attribute displayed on one section map,which can greatly improve the efficiency and accuracy of interpretation,and it is proved that the recognition on low level faults is effective The method based on structure oriented filter coherent enhancement has a good effect on the low level faults detective ability in the three-dimensional seismic model,and it can strengthen the identification ability of the low level faults,which also has good anti-interference ability by the research of anti-interference test.The method based on two time derivations coherent enhancement has a better identification ability on low level faults detection,meanwhile it also can improve the resolution on layer slices.The method based on Hessian matrix coherent enhancement,which can strengthen the ability on fault edge detection and the fault edge position display effect,can also increase the signals along the fault edge which means the signal to noise ratio(SNR)is improved,therefore,the fault combination and the spatial distribution of low level faults can be detected and described in detail.However,these methods have some limitations,such as the method based on two time derivations coherence enhancement takes calculation time-consuming,the method based on Hessian matrix coherent enhancement does not have ideal effect,which means that the later continue research to optimize the processing in order to get better effect is necessary.