The Space Morphology Fine Interpretation And The Water Abundance And Conductivity Comprehensive Analysis Of Xieqiao Karst Collapse Column

Since the 1# and 2# geological anomalous bodies were found by the 3D seismic information interpretation in Xieqiao Colliery in 2002, where have done research for times according to the need of mine production development and security. Based on the data of the original 3D seismic and testing boreholes, China University of Mining and Technology(Beijing) rehandled and interpreted the data of the geological anomalous bodies, which were confirmed as the karst collapse column. The plane configuration of the 1# collapse column was approximately oval, and solid shape of them was a pyramis that presented small top and big bottom. The 2# collapse column consisted of three approximately oval small ones that presentes moniliform on the plane, which was called as “karst collapse belt” because it was distributed in belts.The subsided column buries concealed,with some difficulties of its meticulous depiction of the space form,which cannot be solved by traditional drilling methods. This paper gets the support of the project “The integrated prospecting and the water hazard control of the karst collapse belt and the affected zone in Xieqiao Colliery east wing mining area”. It increases greatly the interpretation accuracy by using the continuity of 3D space of the 3D seismic data, with the data guidance and verification, and also predicts its hydraulic conductivity and abundance. This paper sections as following:(1) It summarized the whole and hydrologic geology characteristicts of Huainan coalfield. Under this frame, it has collected the drilling data of Xieqiao east wing as possible. And it does 17 drilling’s whole and hydrologic geology statistical analysis optimum seeking chosen in I and II line, considering the drilling distributing position, if drilling to the target horizon and collecting effective data, as to the specific geological problem that has to be solved.The analysis results shows that, Xieqiao mining area is located in the south of Huainan synclinoria, it’s hydrogeological characteristics belong to the middle zone of Huainan regional hydrogeologic. As demonstrated by the drilling statistics, locally developed fracture zone and karst cave, water leakage appeared many times. Pumping tests show the 4 coal floor sandstone of east mining area of Xieqiao have low water-richness, while deep limestone have heterogeneity water-richness.(2) This paper does high precisely fine processing on the reseach 3D seismic data, and it uses multi-attribute analysis technology to fine interprets the Xieqiao east wing and the effected zone karst collapse column, based on the characteristics of karst collapse column geologic development and seismic response.It does high resolution processing on the Xieqiao east wing 3D seismic data: analyses the original seismic data characteristics, and makes out the appropriate processing by treating parameters respectively, as to the problem such as narrow frequency band of the original data, the different energy distribution between vertical and transverse, the relatively serious surface wave interference, the obviously static correction. The processed data’s wave group characteristics, formation contact relationship is more precise, the sections and the breakpoint location more accurate. The main target event has good continuity, and the snr increases greatly, which provides highly precise data foundation on subsequent karst collapse belt。This paper does fine interpretation on the high resolution processing data. The interpretation results shoes that thethe overall shape of study area is a monocline, seaondary fold locally development. The strike direction is NNW, tend to SWW. Fault structure is well developed, there are 314 nomal faulst and 1 reverse fault. The collapse zone developed in the northwest area of Xieqiao east wing. extracting dozens kinds of attributes such as the amplitude, the frequency, the waveform and chosing several kinds of sensitive ones by multi-attribute analysis, to comprehensive depicts the karst collapse column(belt) development characteristics.(3) This paper does geology and hydrologic geology statistical analysis on Xieqiao Colliery east wing mining area drilling data. It can be general summarized that the thick ness, the distance, the shape changing characteristics, the karst cave development, leakage and water abundance condition of the coal and rock. It does meticulous depiction of the space form on Xieqiao Colliery east wing karst collapse column, verifying the interpretation results of 3D seismic data, and does revision in some place. Based on these, this paper analyses the formation mechanism of Xieqiao Colliery east wing karst collapse column(belt), combining with relative data from its development history.The characteristics of borehole data statistical shows, the collapse column development zone has following charecteristics: have certain collapse span, but the stratigraphic sequence of the collapse strata is normal; Taiyuan formation and Ordovician strata have large thickness variation; fractured coal and rock has well connectivity along the strata; close to the center of collapse column, the fracture of coal roof become more and large; Taiyuan formation limestone locally developed fractured zone near the boundary of collape column, while Taiyuan formation and Cambrian limeston developed karst caves; the limestone in the collapse development zone is medium to strong water abundant.The characteristics of borehole data statistical shows, the collapse column affected zone has following charecteristics: the thickness and spacing of coal seams are basically normal; Taiyuan formation and Ordovician strata have normal thickness while locally varies widely; fractured coal and rock has well connectivity along the strata; fractures are relatively well developed, the fractured zone of the roof of maine coal seams are lcocally developed, Ordovician limestone developed caves; the 4 coal seam floor sandstone and deep limestone detected leaks; the water abundant of deep limestone in the collapse affected zone is varies greatly.(4) This paper analyses the applicable condition of the Wyllie time-average equation, improving the time-average equation and increases its applicability. By using the Wyllie time-average equation, it builds the relationship between the seismic wave velocity and porosity of the water filling rock body. According to the density-average equation, it builds the relationgship between the density and porosity of the water filling rock body, then building the relationgship between the wave impedance and the porosity. Finally, it can predicts the development condition of the research area porosity by wave impedance. By using the 3D seismic wave impedance inversion technology, it gets the wave impedance characteristics of the target layer, and constructs better wave impedance-porosity model, to gets the changing trendcy of target layer porosity. It analyses the hydraulic conductivity and abundance of Xieqiao Colliery east wing karst collapse belt by comprehensive using the results of the wide-area electromagnetic exploration and the para-flow field side leakage.This paper does the relatively analysis about the logging including density and velocity curve, the coal seam section and the clastic rock(including sandstone, mudstone, and sandy mudstone) and other kinds of logging curves, screening better relative logging curves and rebuilds them in ones that lack of dentity and sound wave curves. Then it builds the initial model, optimal selecting inversion parameters, doing wave impedance inversion, and extracts strata wave impedance characteristics of 1layer mine top and bottom according to the single layer character extracting method.This paper analyses the applicable condition of the Wyllie time-average equation, improving it and building the wave impedance-porosity model with better aaplicability. Based on this, the porosity changing character can be caculated from target layer wave impedance characteristics.Comprehensively using the wide-area electromagnetic exploration and the para-flow field side leakage, according to Xieqiao mine field hydrologic geology condition, it comprehensively analyses the hydraulic conductivity and abundance characteristics of Xieqiao east wing. It can be concluded to the water system relation diagram among the wide-area electromagnetic low resistance anomaly belt, the karst collapse column and the south water system, and also the relation diagram about the I,II line and 13 drillings limestone water system relation diagram, which can provides evidences for subsequent evaluating the system relation degree among study areas. It can be concluded that there should exists a hydraulic conductivity and abundance belt near C3-I limestone, along the 1# karst collapse column-2# karst collapse column – Dongfeng well.(5) According to the analysis about the hydraulic conductivity and abundance in Xieqiao east wing and the effected zone karst collapse column, combining with the background of hydrogeology, it analyses main type of water disaster in Xieqiao east wing from Cenozoic loose sand layer water, 4 coal layer bottom sandstone water, C3-1 limestone water and karst collapse belt water-rich.In a word, this research collects lots of drilling data, and does painstakingly statistical analyses according to the demand. It also does the research on depicting the karst collapse column(belt) development characters and the method of predicting its hydraulic conductivity and abundance. The whole process has gained notable achievement, which has well research and product meanings.