Jia C.,State Key Laboratory of Petroleum Resources and Prospecting |
Jia C.,China National Petroleum Corporation |
Pang X.,State Key Laboratory of Petroleum Resources and Prospecting |
Pang X.,China University of Petroleum - Beijing
Shiyou Xuebao/Acta Petrolei Sinica | Year: 2015
Deep strata of petroliferous basin refer to the formations with the buried depth more than 4 500 m. Till 2010, a total of 200 petroliferous basins have been discovered with the buried depth more than 4 500 m in the whole world, as well as 1 477 deep hydrocarbon reservoirs. In Tarim Basin, the proportion of discovered deep and ultra-deep hydrocarbon reserves was increased from 66% in 2 000 to 92% in 2013, indicating a huge exploration prospect. Over the past two decades, important achievements have been made in research of the following six subjects, i. e., deep structure and geological environment of petroliferous basin, effective reservoirs of deep clastic and carbonate rocks, origin and assessment method of deep hydrocarbons, deep hydrocarbon accumulation and distribution laws, deep hydrocarbon phase characteristics and reservoir preservation. At present, the exploration of deep hydrocarbon is facing a series of challenges. The research on seven aspects should be carried out to break through the current dilemma, including the improvement in the quality of deep data, the increase in deep information detection methods and data processing technologies, the enhancement of study on tectonic process and the evolutionary history of pressure and temperature field, the research on the dynamic process of hydrocarbon reservoir evolution, the enhancement in the research of hydrocarbon geochemistry and resource assessment, the studies with the aim to reveal the genetic mechanism of hydrocarbon reservoir under high temperature and high pressure, low porosity-low permeability and other unconventional conditions, the establishment of new theories for deep hydrocarbon geology and exploration, as well as the development of new matching technologies. © 2015, Editorial Office of ACTA PETROLEI SINICA. All right reserved.
Wang M.,China National Offshore Oil Corporation |
Kang Y.,China University of Petroleum - Beijing |
Kang Y.,State Key Laboratory of Petroleum Resources and Prospecting |
Mao D.,China University of Petroleum - Beijing |
Qin S.,China University of Petroleum - Beijing
Natural Gas Industry | Year: 2013
The dewatering-induced local hydrodynamic field is resulted from the perturbation in the original hydrodynamic field during dewatering and production of CBM. Therefore, it is of great significance to study the dewatering-induced local hydrodynamic field modes and their impact on the CBM gas production, so as to provide guidance for the optimization of CBM drainage beds in production wells. The CBM gas wells in a certain coal field at the southeastern margin of the Ordos Basin present a great variance in the dynamic performance of CBM gas production. Considering the structural positions and original hydrodynamic fields of different drainage wells, three dewatering-induced local hydrodynamic modes, resulted from CBM production, were identified, i.e., the effective perturbation mode, aquifer intrusion mode, and freshwater supply mode. For the local hydrodynamic field of the first mode, the outlet water comes from the coalbed water, thus the CBM well is characterized by fast gas production and high productivity; for the local hydrodynamic fields of the latter two modes, the outlet water partially or even mostly comes from the aquifer in the neighborhood or the near-surface freshwater, which belongs to the invalid drainage, resulting in slow production and low productivity of CBM wells. Based on the local hydrodynamic mode, the coalbed with strong aquifer should be avoided for near-fault drainage wells; meanwhile, the well sites should be laid out away from the supply areas of near-surface freshwater.
Lai J.,China University of Petroleum - Beijing |
Wang G.,China University of Petroleum - Beijing |
Wang G.,State Key Laboratory of Petroleum Resources and Prospecting |
Chen M.,China University of Petroleum - Beijing |
And 5 more authors.
Shiyou Kantan Yu Kaifa/Petroleum Exploration and Development | Year: 2013
The sedimentary facies, diagenetic facies and fracture facies of the Upper Triassic Yanchang Formation Member 8 (Chang 8) reservoir in the Jiyuan region were studied using core observation, thin section, logging and drilling data. On this basis, the petrophysical faices of Chang 8 oil layers were examined to evaluate the pore structure by classification and predict zones with high porosity and permeability. The petrophysical facies were divided according to the superposition and combination of sedimentary facies, diagenetic facies and fracture facies. A number of petrophysical facies of Chang 8 oil layers such as underwater distributary channel, dissolution of unstable components, high-angle fracture, were identified in this way. Four main categories of petrophysical facies were summed up according to the constructive and destructive impact of sedimentary facies, diagenetic facies and fracture facies on the reservoir property and pore structure of Chang 8 oil layers. Since the reservoir quality index (RQI) is an optimal indicator for describing the reservoir micro-pore structure quantitatively, the value of RQI of different petrophysical facies was calculated respectively. So the classification and evaluation of Chang 8 reservoir pore structure in a single well were realized by the division of petrophysical facies combined with logging data. At last, the vertical and horizontal distribution of sedimentary micro-facies and diagenetic facies of each single layer of Chang 8 oil layers were mapped, the distribution of favorable petrophysical facies can be used to predict the zones with high porosity and permeability.
Tong H.-M.,State Key Laboratory of Petroleum Resources and Prospecting
Geological Bulletin of China | Year: 2010
In this paper, applying target sandbox modeling results of "uncoordinated extension" and the new mechanical model of britde faulting-"non-coordination criterion", the controlling factors of fault formation and evolution are analyzed, and a new model of fault formation and evolution, which is called the "uncoordinated extension" model, is proposed. According to the model, the progressive deformation process of "uncoordinated extension" is the root cause which leads to the complexity of fault system in rift basins. Because the activity of each pre-existing fabric (mainly pre-existing fault) of different trend, property and size in the basement is different, it will lead to different, controlled faults in the strike, formation order and size and the complicated fault assemblage forms, "uncoordinated extension" is the basic patterns of fault formation and evolution, the complicated fault system can be formed progressively in progressive extension process under "uncoordinated extension" with unchanged extension direction. It is pointed out that the fault system in the rift basin is relatively complex, but the fault formation and evolution is orderly, and there is a law in the fault distribution, which can be analyzed and predicted with "non-coordination criterion".
Lan X.,Ocean University of China |
Lu X.,China University of Petroleum - Beijing |
Lu X.,State Key Laboratory of Petroleum Resources and Prospecting
Turkish Journal of Earth Sciences | Year: 2014
The Yingshan Formation, located on the Tazhong Northern Slope, contains oil-and gas-rich layers with the reserves of about 700 × 106 TOE. The high-resistivity inner layers isolate the hydrocarbon bearing zones and form the sequential sets of reservoir bed-seal assemblages in a vertical direction within the Yingshan Formation, which is directly bound above by a micritic carbonate cap rock that is overlain by the 3rd to 5th members of the Lianglitag Formation. The sealing capability of the cap rock and inner barrier layers was evaluated macroscopically and microscopically in terms of the core breakthrough pressure and thin-section identification. The evaluation parameters were extracted from the statistical analysis of drilling and logging data. The 3rd to 5th members of the Lianglitag Formation are more shaly, but the inner barrier layers in the Yingshan Formation are more dolomitic. Argillaceous limestone is more capable of sealing oil and gas zones than micritic limestone. The 3rd to 5th members of the Lianglitag Formation, of which the gamma ray response and core displacement pressure are greater than 20 API and 14 MPa, respectively, provide good sealing with thicknesses of more than 100 m and have better sealing with thickness of more than 200 m. For the same porosity, dolomite has lower coreflood displacement pressure than limestone. The difference in coreflood displacement pressure between the barrier layers and the underlying reservoir bed is 6 MPa, the cutoff value for sealing capability. Carbonate sealing was controlled by early sedimentation and was influenced by late diagenesis. The direct cap rock is dense and has cement content of more than 10%, up to 31%. The reservoir bed has cement content of less than 10%. Generally, the direct cap rock and the inner barrier layers are relatively stable on the lateral distribution. © TÜBITAK.