Research And Application Of Assessment Methods To Source Rock In Binbei Area Of Songliao Basin

Binbei area refers to the northern of Binzhou railway in north of Songliao Basin. It occupies nearly 2/3 to explored area of north of Songliao Basin. The last four decades, oil & gas explore in Binbei area have undergone several cycle, and have not make a substantive breakthrough yet. The resource potential is the most essential question restricted to explore, therefore, This article started with the hydrocarbon source rock condition, studied emphatically the Assessment methods of hydrocarbon source rock condition and the resources quantity computation. Computed Dividing 4 main geological periods and using three methods and 4 main hydrocarbons sources rock layer to 18 two level of tectonic elements, including crudity and low mature oil. Forecasted the advantageous prospecting region of oil & gas resources after these. Added to this, studied alone the assessment method to biogenic gas, and forecasted the advantageous prospecting region. In connection with generating hydrocarbon quantity, used the methods of chemical kinetics, thermal simulation experiment and probability statistics three methods separately, carried on the computation and contrast analysis. The results received from thermal simulation experiment are smaller than the results received from chemical kinetics method. Synthesizing several main reasons to believe that, the chemical kinetics method does not lose the light hydrocarbon component, may calculate the crudity and low mature oil, has the more credible rationale, has represented the development direction of hydrocarbon source rock quantitative evaluation research. The probability statistical method was different to the thermal simulation experiment and the chemical kinetics method. It obtained a probability distribution scope of generating hydrocarbon quantity. It reflected the uncertainty of geological parameters and has avoided general judgment of only one value. By way of a risk assessment method, in the aspect computing generating hydrocarbon quantity, it has the same forecast function with method of basin simulation to the geological factor polytropy and uncertainty, moreover it is more simple and easy to put into practice. So it can be taken as an auxiliary method to the exploration risk assessment. When computing ejecting hydrocarbon quantity, used the material-balance method of "generating hydrocarbon subtract remnant hydrocarbon is equal to ejecting hydrocarbon". So considered only the remnant hydrocarbon quantity. On computing the remnant oil, used the parameters of chloroform asphalt "A" and the thermolysis residual hydrocarbon "S1" after adjusts of light hydrocarbon compensate. Considered adsorption hydrocarbon, the dissolved hydrocarbon and dissociation hydrocarbon three forms. The remnant gas computation had considered rock adsorbed gas, oil dissolve gas and water-soluble gas three forms. Biogenic gas is not same obviously to petroliferous gas and coal gas. Biogenic gas was mainly formed low mature stage which evolves to the organic matter. It formed by the microorganism food chain responding. Its formation mechanism is also different. Therefore many methods of researching crudity and low mature oil were not suitable to the biogenic gas research. Start with the formation mechanism, the geochemistry characteristics of biological gas source rock, the transformation characteristics of organic matter by microorganism activity, the source rock differences among biogenic gas, coal gas, high mature marine facies, crudity and low mature hydrocarbon and petroleum, determined suitable evaluation criterion according to the Binbei geological characteristic. The research confirmed that, there existed the evidences of microorganism transformation and input in extract of most source rock samples in Binbei of Songliao Basin. It explained that there were the process of microorganism transformation organic widely in this area, and had begun to produce methane. With regard to the resources quantity computation, in computing conventional oil & gas, here considered under the ideal condition convergence factor, then the structure movement, the cap rock condition, the ejecting hydrocarbon intensity, the hydrodynamic factor four aspects main geology factor to appraise the oil & gas resources quantity. In computing biogenic gas, used factor of created gas which received from basin biogenic simulation, then computed with generation and conglomeration method. Acquired convergence coefficient using analogy method. Appraised the biologic gas resources quantity considered simultaneously the different tectonic element, the cap rock condition, the hydrodynamic condition, the organic matter type, the union geology characteristic and source-reservoir-caprock assemblage and so on factors. By analyzing the resource potential of Binbei area, several conclusions can be figured out. The resource potential is fewer by a long way than the mostly prospecting region of Songliao basin, but it is worth exploring compared with any periphery basin of Daqing prospecting region. The most advantageous area include Heiyupao sag, Mingshui terrace, north of the Daqing placanticline, Sanzhao sag and Qijia-Gulong sag, south of Suihua sag, which approach the middle of Binzhou railway. The advantageous area of biogenic gas locate in Suihua sag, Mingshui terrace, Yian sag, Suiling anticlinal zone, Heiyupao sag, Wuyuer sag,, Qianyuan structural zone, Keshan-Yilong anticlinal zone and so on. In the section, there are biological gas in many oil layers, for examples, Sartu, Putaohua, Gaotaizi, Fuyu and Yangdachengzi oil layer. There is only one high yield natural gas well in Binbei area. Dong 5 well lies in the south of Suihua sag. The natural gas has characteristic of biogenic gas obviously. The gas should be biogenic gas or be gas mixture in which there is primarily biogenic gas.