Mao G.-Z.,Northwest University, China |
Mao G.-Z.,Shandong Provincial Key Laboratory of Depositional Mineralization and Sedimentary Minerals |
Mao G.-Z.,Shandong University of Science and Technology |
Liu C.-Y.,Northwest University, China |
And 4 more authors.
Zhongguo Shiyou Daxue Xuebao (Ziran Kexue Ban)/Journal of China University of Petroleum (Edition of Natural Science) | Year: 2012
Hydrocarbon-generating simulation experiment was proceeded using hydrocarbon source rock containing kerogen type I with uranium (sandstone uranium ore) added. The effects of uranium on the hydrocarbon generation by relevant parameters of simulation experiment products were studied comparatively. The results show that uranium can facilitate the long-chain hydrocarbons cracking into low molecular weight hydrocarbons at the temperature above 400 °C, as a result the molecular weight of hydrocarbons products is lowered. The degree of dry gas increases, while the CO 2 and H 2 are largely generated, and the uranium lowered the variation temperature for about 50 °C. Uranium can lower the peak temperature of total liquid hydrocarbons generating. 350 °C is the transition temperature of alkenes yield, above which alkenes changes into alkanes. Uranium can enhance the isomerization of alkene produced in the simulating experiment, and make the molecule lattice of alkene member arraying more closely. It's mature of products in the characteristic parameters of group composition, saturated hydrocarbon GC, biomarkers generated in the hydrocarbon-generating simulation experiment of hydrocarbons source rock with uranium. The uranium may enhance the maturity of organic matters. The existence of uranium in hydrocarbon source rocks is favorable to the generation of the immature hydrocarbons. It means that uranium in hydrocarbon source rocks is maybe one of the inorganic accelerating factors of the hydrocarbon generation. Such a small amount of hydrocarbon generated in advance can change the reservoir into a lipophilic reservoir, and it provides advantage conditions for migration and accumulation of late large-scale generated hydrocarbons. It makes the dense reservoir becoming large-scale industrial hydrocarbon reservoirs.
Li J.,Petrochina |
Li Z.,Petrochina |
Wang D.,Petrochina |
Cheng H.,Petrochina |
And 4 more authors.
Shiyou Xuebao/Acta Petrolei Sinica | Year: 2013
This study investigates the content of N2 and the origin and source of nitrogen isotope composition in different tectonic zones of Tarim Basin by examining the geochemical characteristics of nitrogen mched natural gas in the major oil-gas fields in Tarim Basin. Results show that the N2 content is determined by the type and maturity of natural gas. Oil-type gas generally contains more than 5% N2 and is mainly distributed in Paleozoic strata in the central uplift and Tabei uplift. Coal-type gas generally contains less than 5% N2 and is mainly found in Mesozoic-Cenozoic strata in Kuqa depression, Tabei uplift, and Taxinan depression. The content of N2 in natural gas is highest in the stage of maturity and gradually decreases with increasing maturity. The nitrogen isotope fractionation of natural gas is closely related to the type of natural gas, and light-and heavy-nitrogen isotope fractions are respectively found in natural gas in oil-and coal-type gas reservoirs. The N2 origin of natural gas in the major oil-gas fields in Tarim Basin is further analyzed. Results show that the N2 composition of natural gas in most of the oil-gas fields in Tarim Basin have identical origin with hydrocarbons gases in the same reservoirs, i.e., the products of source rocks in the stages of maturity and high to post maturity. An exception is natural gas in Akemomu gas field, which is associated with obvious mixing of mantle-derived N2.
Lang X.-J.,Shandong University of Science and Technology |
Yu J.-F.,Shandong University of Science and Technology |
Yu J.-F.,Shandong Provincial Key Laboratory of Depositional Mineralization and Sedimentary Minerals |
Fu W.-Z.,Shandong University of Science and Technology |
And 2 more authors.
Meitan Xuebao/Journal of the China Coal Society | Year: 2012
Chegu29 wells which distributed from southwest to northeast were selected for the study of Milankovitch cycle. With the help of Matlab software and Wavelet transform toolbox and on the basis of the previously constructed recognition method of Milankovitch cycle, cycles identified from logging data of seven wells were selected and then the dominant Milankovitch cycles recorded in strata were determined. The development regularity of Milankovitch cycle and the development characteristic of delta and basin were revealed, the age of strata was calibrated by the analysis of sedimentary rate and depositional thickness. It is found that Milankovitch cycles are widely developed in Chezhen Sag. The development of the low-frequency informations is inferior to the high-frequency ones. The delta and basin exhibit difference of expansion-shrinking-expansion from southwest to northeast, the relatively low-frequency cycles(Eccentricity) are prone to be preserved in the stratum whose sedimentary rate is lower, the high-frequency ones(Precession, Obliquity)are prone to be preserved in the stratum whose sedimentary rate is higher. According to calculation, the age of top boundary of the Member 1 of Shahejie Formation ranges from 31.5 to 32.5 Ma, and the age of top boundary of the Member 2 of Shahejie Formation is from 32.7 to 33.2 Ma. The ages of the uppermost strata of the Member 1 of Shahejie Formation of Chegu29, Che35, Chegu203, Dagu63 wells are 32.4, 32.4, 32.1, 32.5 Ma respectively.
Cheng H.,Shandong Provincial Key Laboratory of Depositional Mineralization and Sedimentary Minerals |
Cheng H.,Petrochina |
Wei G.,Petrochina |
Ran Q.,Petrochina |
And 4 more authors.
Natural Gas Industry | Year: 2013
Solid bitumen is well developed in the Lower Paleozoic in the eastern Tarim Basin. As solid bitumen is the product of crude oil cracking, its characteristics and periods of formation are indicative of the hydrocarbon generation and migration in the study area. Through analyzing its accumulation forms, occurrences, types, content and distribution, we divided the solid bitumen in the Lower Paleozoic there into two types: in-situ bitumen and reservoir bitumen. Seven sub-types were further identified according to their occurrences. The content of solid bitumen is not high as a whole in the study area. The in-situ bitumen is mainly distributed in the carbonaceous mudstones, while the reservoir bitumen mainly occurs in carbonates. The in-situ bitumen mainly occurs in the Lower Paleozoic, while the reservoir bitumen only occurs in the Upper Cambrian dolomites and the Mid-Lower Ordovician limestones. In general, the content of bitumen is the highest in the Cambrian. According to the characteristics of reflectivity, there are different phases of solid bitumen in different tectonic units of the region. One is the single-peak bitumen, which is only influenced by the sedimentation and mainly distributed in Kurle nose-uplift and west of Lop Nor nose-uplift. The other is the dual-peak bitumen, which is influenced by the sedimentation and one tectothermal event, and is mainly distributed in the Yingjisu sag and the area to its southeast. The third is the tri-peak even multiple-peak bitumen, which is influenced by the sedimentation and two tectothermal events, and is mainly distributed in Gucheng nose-uplift and Tadong low uplift. It is concluded that not only palaeo-oil reservoirs possibly occurred in the Lower Paleozoic in the uplift zones and slope zones of the eastern Tarim Basin, but also secondary oil/gas reservoirs formed through late re-accumulation of hydrocarbons from multiple-stage cracking of crude oil.
Shi L.,Shandong Provincial Key Laboratory of Depositional Mineralization and Sedimentary Minerals |
Shi L.,Shandong University of Science and Technology |
Qiu M.,Shandong University of Science and Technology |
Wei W.,Shandong University of Science and Technology |
And 2 more authors.
International Journal of Mining Science and Technology | Year: 2014
The method of singular coefficient of water inrush to achieve safety mining has limitation and one sidedness. Aiming at the problem above, large amounts of data about water inrush were collected. Then the data, including the maximum water inrush, water inrush coefficient and water abundance in aquifers of working face, were processed by the statistical analysis. The analysis results indicate that both water inrush coefficient and water abundance in aquifers should be taken into consideration when evaluating the danger of water inrush from coal seam floor. The prediction model of safe-mining evaluation grade was built by using the support vector machine, and the result shows that this model has high classification accuracy. A feasible classification system of water-inrush safety evaluation can be got by using the data visualization method which makes the implicit support vector machine models explicit. © 2014 Published by Elsevier B.V. on behalf of China University of Mining & Technology.