The Analysis Of Basin Dynamics In Bohaiwan Region And Study On Geological Hazards Of Oilfield

Using the theories, methods and technologies of basin dynamics and tectonics andstructure, applying petroleum furthest, earthquake and hydrology data, combining thequalitative ways with quantitative ones, the structural system and dynamic characters,formation and evolvement of different tectonic order of Bohaiwan Basin were studied, andwhat they controlled and effected on the oil region, oil field, and the generation,transformation, accumulation, reservation and destruction were demonstrated. Therelationship, which is between structural system and dynamics environment of differenttectonic order, and the formation and distribution of the geological hazards of oilfield inBohaiwan Basin, were discussed. All of which were as a scientific basis of the security ofoilfield and efficient production.The concept of geological hazards of oilfield was put forward and expatiated. Thecharacters and distribution of main type geological hazards of oilfield were elaborated. Soit is held that there were many geological hazards of oilfield developed in Bohaiwan Basin,such as casing deformation of oil and water wells, induced seismicity, surficialdeformation, spout water and oil in geosuture and natural earthquake. The dynamicmechanism of different geological hazard of oilfield in Bohaiwan Basin was discussed. Itwas brought out that the formation, distribution and evolution of geologic hazards ofoilfield in Bohaiwan Basin were controlled by the structural system and structural stressfield with different order. The geologic hazards of oilfield took place frequently andextensively always in transforming region, compound region and reversal belt of presentstress field, physical field, chemical field, and reservoir flow field.By analyzing and studying the formation and evolution of basin dynamics in differenttectonic order such as Bohaiwan Basin, Jiyang Depression and Dongying Sag, it wassupposed that Bohaiwan Basin was formed by the compression and sinistral slip stressfield in Mesozoic era and was rebuilt and complicated by the extension, dextral strike slipand reversal stress field in Caenozoic era, so the structural cosmetics was formednowadays. The structural system and structural stress field of different tectonic order weredeveloped in Bohaiwan Basin. The structural system character, distribution regulation anddynamic revolution character of different tectonic order, such as basin, depression, sag andstructural belt, were studied in the inner of Bohaiwan Basin. The study point out that thestructural system with lower tectonic order were controlled by the higher order in theBohaiwan Basin.Using kinds of data and information about oilfield geology, earthquake and hydrology,and combining the qualitative method with the quantitative one, the study was believedthat hydrocarbon formation and distribution were controlled by the structural system ofdifferent tectonic order and structural dynamics, which was about the formationmechanism and distribution regulation of oil region, petroleum accumulation, oil field andreservoir inside of the Bohaiwan Basin.As an example, the oil-controlled fault sealing of different order in Dongying Sagwas analyzed and studied. The sealing dynamics mechanism was studied, and also severalmodels of sealing dynamics, such as main stress, time configuration, mudstone moistfactor of oil-controlled fault in Dongying Sag, were built. After studying the fault sealingof lower sequence fault affected and controlled by lower order of dynamics, the high andarea of reservoir may be forecasted.Methods and technology were established to study the formation and distribution ofvarious oil region, oil field and reservoir, and geological hazards of oilfield by using basindynamics of different order.