Oil And Gas Geological Condition And Prospect Evaluation In The Peripheral Down-Faulted Basins Group Of Mesozoic And Cenozoic Era, Daqing Exploration Area

This thesis is completed under the support of the investigation and appraisal project of the national oil and gas resources strategy electoral district-the comprehensive evaluationof oil and gas geological quality of the Cainozoic Era breaks falls basin in the periphery of Daqing prospecting region (XQ-2004-07-06). The research area is the periphery basin group of Daqing prospecting region, which is distributed within the boundaries of Heilongjiang Province, Hulunbeier City of InnerMongolia Autonomous Region and Jilin Province. Besides Songliao basin, and Hairlar basin, there are 28 sedimentary basins with an area of more than 200km2, and the total area of the basin group amounts to 18.53×104 km2. These basins are close to an important oil and gas production area--Songliao basin in our country, but the proving rate of these basins is relatively low, which demonstrates that they still have much exploration potentiality. The exploration achievement obtained unceasingly in recent years, has continuously increased the oil reserves of our country, all of which has indicated the urgency and importance of further development of oil-gas exploration in periphery basin of Daqing prospecting region.The oil-gas prospect appraisal is an important link in the oil-gas exploration process which involves many geological data and the assessment methods. Through comprehensive analysis of the multiple source geoscience information, the oil-gas prospect appraisal makes an overall assessment of oil-gas resources potentiality in a certain area, and then optimize the advantageous area belt. The oil-gas prospect appraisal is a kind of system engineering, which provides policy-making support for further exploration and development and plays an influential role in the oil-gas exploration and development.Along with the further development of the oil-gas exploration work, massive multiple source geoscience information has been obtained, such as geology, geophysics, geochemistry, remote sensing material and so on. However, it is not only time-consuming and hard sledding to withdraw the useful information from these numerous material to carry on this work, but also needs lots of investment. Moreover, the anticipated effect is difficult to be achieved, and also, the method and technology cannot be promoted well. Along with the rapid development of computer technology, it has been widely used in the scientific research of various trades and occupations, A broad prospect for carrying on the oil-gas resource appraisal has been developed by using the computer technology to process the massive geoscience material fast and effectively .GIS has the formidable spatial analysis function to geoscience data, can obtain the concealed important conclusion from the known geoscience data and derives new information, meanwhile , as a model of the real world, it will make a generalized analysis of the appraisal results and function of the real world's each side thought. Therefore , using GIS is an important way to make full use of known data and extract latent information as well as raises the oil-gas forecasting level. To carry on the oil-gas resource appraisal , massive petroleum geology factors must be taken into consider ,which include lots of conditions, the amount of resources and the economic evaluation, such as foundation stratum research ,source bed, reservoir bed , cap bed and their combination relations of target zone, trap,oil-gas migration and the preservation and so on. All these factors are related to certain geography space position, have spatial information characteristic. Based on the analysis and research of the petroleum geology theory, the petroleum geologists express the above various factors by the way of graphic mode, and finally achieve the generalized evaluation goal of the oil-gas resources through the overall analysis of all kinds of graphic document.From the history of study and current situation, the periphery basin exploration and the research degree are low. In the central and western basin group, the study of petroleum geology is relatively weak, mostly giving priority to non-earthquake information on the Earth's materials that mainly focus on large-scale gravity and magnetic exploration, magnetotelluric sounding over the oil field investigation and geological survey; Although the eastern part of the basin group has been the exploration focus of the external Songliao Basin, the basin is many and small, highly divided, post-structural role in the transformation and strong destruction, which exploration and research is difficult, so the overall extent of the exploration area are lower, moreover various basins' research degree phase difference is disparate. On this basis, our predecessors in the periphery of the basin, carried out on a lot of research work, but in the main basin, such as the structural layer, phase of tectonic evolution, basin type, thermal history and the basin hydrocarbon compound maturity history, the advantageous area belt forecast and so on that the question research still has certain difference, and is restricting the periphery basin oil gas prospect appraisal.The periphery basin of Daqing prospecting region is mostly the transformation- superposition basin. The overall exploration degree is relatively low, which is characterized by the multi-cover hydrocarbon source rock, many kinds combination of reservoir bed and cap bed, the multi crude and platoon hydrocarbon and multi-stage petroleum reservoir characteristics and so on. It is extrapolated that there exist sources of many kinds of oil-gases. Usually exploration goal level burying depth to be big, experience long-term evolution, the oil gas pool charge history is complex and the oil-gas distribution rule has been restricted by many kinds of factors. The complexity of oil-gas's formation and accumulation in the superposition basin has determined that the oil-gas prospect appraisal could not be carried on with conventional and simple norm or rule.Therefore, this article when carries on the oil gas prospect appraisal to the research area, take the petroleum geology as the master line, emphasizing the basis of geological conditions on the formation and accumulation of control oil and gas, integrated research results based the analysis on pre-Mesozoic basement structure and evolution, the Mesozoic-Cainozoic Era basin structure, the ancient geography pattern, hydrocarbon source rock characteristic and so on. Utilizing the multi-methods, various material and achievement information, Daqing Exploration Area is divided into three basin groups of eastern, central and western, six-storey department exploration , seven Basin system, six exploration formation ,four kinds of basin types, three kinds of superimposition relationship ,and experiences five stages of basin tectonic evolution. This space and time frame has controlled growth oil and gas basic pattern in the research area.Under this space and time frame, Using the geological analogy method, from three level's geological feature of the region, the basin, the internal of basin, carries on research on control migration and accumulation basic geologic factors research such as regional geology background, geostructure evolvement, basin structure and evolvement, deposition and backfill history and volcanic activity .Moreover, find out the relationship between with oil and gas and composition and structure of oil and gas basin fundus, volcanic rocks and the role of volcanic, basin tectonic, basin filling sequence, basin evolution, regional fault. Finally, carry through sorting preferred Basin from basic geological framework. Using basin modeling techniques, carry on sorting preferred Basin by simulation results of terra history, thermal history, mature history. Under multi parameter conditions, Making full use of computer technology, carry on sorting preferred basin by condition such as basic geological factors, and source bed, reservoir bed, cap bed, combination relationship. Establishing evaluation model of oil and gas basing on neural network to determine parameters weight, The thesis carries on predicting favorable play for basins of higher exploration levels such as Tangyuan– Fangzheng and west of Sanjiang and Yanji basin by multi-source information superimposed method basing on PrtroGIAS. For basins of lower exploration levels such as Dayangshu and Sunwu-Jiayin and Mohe basins, The authors carries on forecasts for oil and gas and proposes the main exploration area and the strategic prospect area by up-to-date information of MT, gravity and magnetic inversion and seismic interpretation. The final results obtained the understanding of the following:①P utting forward five evolution stages experienced, development 4 kinds of basin types and 3 kinds of superimposition relations in Basins of study areaOn the basis of deeply researching about earth structure evolvement in the study area and the adjacent areas, This thesis proposed the research area had experienced five major stages of basin structure evolution, namely Late Triassic - Early Jurassic and Middle Jurassic and Late Jurassic-Early Cretaceous and Late Cretaceous and Paleogene. Different times the intensity and way of tectonic movement are some differences in eastern, central and western of study area; The eastern area take place thrusting nappe structure, while the Cainozoic Era has superimposed along the region branch break growth linear rift valley basin as a characteristic; The features of central region ware that development with a complete rift and depression in two stages of the rift basin ;According to different spatial relationship during Basin formation, the western area take foreland basin(compressional basins) in early -middle Jurassic period and volcano down-fault basin in early chalk volcano period as characteristic. The west main growth foreland \ down-fault -type of superposition basin as characteristic ,while the central area main take down-fault\ depression -type of superposition basin and the eastern area take rift valley\ down-fault \compression \draw dispart-type of superposition basin as characteristic. These three kinds of superimposition relations reflected obvious difference from evolve history in western,eastern and central areas of three basin groups of the research area in Mesozoic-Cainozoic Era.②T ime and space pattern of oil-gas growth of Mesozoic-Cainozoic Era basin determined in the periphery of Daqing prospecting regionIn the horizontal by comprehensive study on structure subarea, basin-fill sequences and basin tectonic evolution, The research area may divide into the eastern part, middle, the western part of oil and gas bearing basin group by the boundary of Jiayin-Mudanjiang hybrid rocks belt and Nenjiang River-Balihan stretch-track-slip tectonic zone. And Dayangshu basin ,which belong to the western basin generally, through analysis of causes of formation between with Dayangshu basin and Songliao Basin, Dayangshu basin came into being down-faulted basins system along western margin of Nenjiang - Kailu breaks, so it is believed that belong to central basin group.According to basins structure characteristic, deposition backfill sequence and evolved history for 14 basins in the research area and various basins in adjacent areas, The thesis classified as seven basin system (or basin system)for 14 basins, whichⅠ,Ⅲ,Ⅴbasin system has been access to oil and gas breakthrough, so Sunwu-Jiayin basin, Dayangshu basin, Gehe-Labudalin basin and Tangyuan- Fangzheng down-faulted basins are speculated to have the big oil gas prospect by contrasting with regional basic geological conditionsIn the vertical, by contrasting stratum with Songliao basin and Hailar Basin, the exploration layers are divided into six exploration strata series (including Carboniferous - Permian), in which, The first, the second and the third layer are worth paying attention to important exploration strata series; The fourth - the sixth exploration strata series have obtained the industry oil and gas current in Daqing and Daqing periphery; The fourth and the fifth exploration strata series oil and gas contribution strata in middle bearing oil and gas basin group ;The fourth exploration strata series is oil and gas contribution strata in west bearing oil and gas basin group ;The sixth exploration strata series is oil and gas contribution strata in eastern bearing oil and gas basin group.This space and time frame has controlled growth oil and gas basic pattern in the research area.③Establishing the geology analogous model of the prospect appraisal of oil-gas basinAccording to the structure and composition of basin basement, basin types, evolution basin evolution and comprehensive study about oil-gas geological condition, the research area mainly includes 5 types of oil-gas prospect geology analogy evaluation models, which are the remaining basin and down-fault\ depression of double-decked basin and down-fault and compression and pull-apart basin. Eastern oil-gas basin groups mainly include the remaining basin and pull-apart basin, while the middle oil-gas basin group mainly bears the down-fault\ depression basin, and the western area mainly bears down-fault and compression basin. These basins can be regarded as a scale, and make a comparison with these 5 types of typical basins in the research area in order to forecast the oil-gas prospect.④Using variety of methods to carrying on sorting preferred basin in Daqing periphery basinsUsing the geological analogy method, from three level's geological feature of the region, the basin, the internal of basin, carries on research on control basic geologic factors of formation and migration and accumulation such as regional geology background and geostructure evolvement and basin structure and evolvement and deposition and backfill history and volcanic activity .Moreover, finding out the relationship between with oil and gas and composition and structure of oil and gas basin fundus and volcanic rocks and the role of volcanic and basin tectonic and basin filling sequence and basin evolution and regional fault. Finally ,carrying through sorting preferred basin from basic geological framework. Using basin modeling techniques, carrying on sorting preferred basin by simulation results of terra history and thermal history and mature history. Under multi parameter conditions, Making full use of computer technology, carry on sorting preferred basin by condition such as basic geological factors and source bed and reservoir bed and cap bed and combination relationship. The authors establish appraise model and make use of multiplication law to preferred sort and queue. Finally, the authors sort and queue 6 key basins such as Tangyuan - Fangzgeng, dayangshu, Sanjiang, Yanji, Sunwu - Jiayin,Mohe basins by synthetizing three methods⑤Completed oil and gas prospect evaluation for keystone basin and favorable play evaluation for major exploration layer in keystone basinFor Tangyuan - Fangzheng, West of Sanjiang basin and Yanji basin which have more of the wells, higher exploration levels, rich oil gas material Through a number of known oil and gas characteristics attribute value of favorable play for network learning training by using artificial neural network, then determined parameters weight and established evaluation model of oil and gas, The thesis carries on predicting favorable play basing on PrtroGIAS by multi-source information superimposed method.The result is as the following: Xin-an villages group of Tangyuan down-fault are been divided into 3 advantageous exploration areas, namely Rongfeng-Shengli-Dongfa syncline area and Dongxing-Jixiang structure area and Shuangxing-Xinhua syncline area and; Xin-an villages group of Fangzheng down-fault are been divided into 3 advantageous exploration areas, namely Baoxing structure area and Xiaolantun structure area and Zuoshugang slop break and Deshan syncline area and Fang D4 structure area and Xiangshun structure area; Chengzihe group of Suibin depression, Sanjiang basin are been divided into2 advantageous exploration areas, namely Bincan -1belt in Nandalinzi sag and Beian belt in eastern slopes; Dalazi group of Yanji basin are been divided into 3 advantageous exploration areas, namely Chaoyangchuan-Tongfusi and the peripheral of Yanji city and Zhuangyandong-Chongming, which are located in Chaoyang Sichuan sag and Qingchaguan sag and Dexin sag ;For basins of lower exploration levels such as Dayangshu, Sunwu-Jiayin and Mohe, The authors carries on forecasts for oil and gas and proposes the main exploration area and the strategic prospect area by up-to-date information of MT, gravity and magnetic inversion and seismic interpretation.⑥Proposing three new exploration domains which are worth paying attention to .Based on the comprehensive research of foundation geology in the entire district, the authors has proposed three worthwhile exploration strata series, namely , Carboniferous– Permian in the basin depth of Songliao basin and Upper Triassic- Lower Jurassic in the basin depth of in the eastern part of big three river basin and middle Jurassic in the Mohe basin, while these exploration strata series are worth paying attention to .