Natural Resources Research - Identifying lithology from well logs is an important step in deep prospecting and resource estimation. Various machine learning algorithms have been adopted to identify... 相似文献
The Paleogene upper Xiaganchaigou Formation (E32) is the most important source rock and reservoir in the Qaidam Basin. However, there are few studies on the processes of hydrocarbon accumulation in this formation; therefore, its hydrocarbon resource potential has not been estimated reasonably. This paper evaluates the hydrocarbon generation properties in light of an improved hydrocarbon generation and expulsion potential model. According to the geochemical characteristics of source rocks and the petrological features of reservoirs, the potentials of different resource types, including conventional oil, tight oil and shale oil, are quantified by combining the buoyancy-driven hydrocarbon accumulation depth (BHAD) and the lower limit for movable resource abundance. The results show that the source rocks are characterized by a large thickness (more than 1000 m), moderate organic matter content, high marginal maturity and a high conversion rate (50% hydrocarbons have been discharged before Ro?=?1%), which provide sufficient oil sources for reservoir formation. Moreover, the reservoirs in the Qaidam Basin consist mainly of low-porosity and low-permeability tight carbonates (porosity of 4.7% and permeability less than 1 mD). The maximum hydrocarbon generation, expulsion, retention and movable retention intensities at present are 350?×?104 t/km2, 250?×?104 t/km2, 130?×?104 t/km2 and 125?×?104 t/km2, respectively. The thresholds of hydrocarbon generation, expulsion and BHAD were 0.46% Ro, 0.67% Ro and 0.7% Ro, respectively. Moreover, the dynamic evolution process of hydrocarbon accumulation was divided into three evolution stages, namely, (a) initial hydrocarbon accumulation, (b) conventional hydrocarbon reservoir and shale oil accumulation and (c) unconventional tight oil accumulation. The conventional oil, tight oil and movable shale oil resource potentials were 10.44?×?108 t, 51.9?×?108 t and 390?×?108 t, respectively. This study demonstrates the good resource prospects of E32 in the Qaidam Basin. A comprehensive workflow for unconventional petroleum resource potential evaluation is provided, and it has certain reference significance for other petroliferous basins, especially those in the early unconventional hydrocarbon exploration stage.
Combining the advantages of numerical simulation with experimental testing, real-time dynamic substructure (RTDS) testing provides a new experimental method for the investigation of engineered structures. However, not all unmodeled parts can be physically tested, as testing is often limited by the capacity of the test facility. Model updating is a good option to improve the modeling accuracy for numerical substructures in RTDS. In this study, a model updating method is introduced, which has great performance in describing this nonlinearity. In order to determine the optimal parameters in this model, an Unscented Kalman Filter (UKF)-based algorithm was applied to extract the knowledge contained in the sensors data. All the parameters that need to be identified are listed as the extended state variables, and the identification was achieved via the step-by-step state prediction and state update process. Effectiveness of the proposed method was verified through a group of experimental data, and results showed good agreement. Furthermore, the proposed method was compared with the Extended Kalman Filter (EKF)-based method, and better accuracy was easily found. The proposed parameter identification method has great applicability for structural objects with nonlinear behaviors and could be extended to research in other engineering fields. 相似文献
Protein kinase C(PKC) has a crucial role in signal transduction for a variety of biologically active substances which activate cellular functions and proliferation. We previously isolated the full-length PKC gene from Dunaliella salina(Ds PKC) using rapid amplification of cDNA ends(RACE) and RT-PCR methods. And we submitted the mRNA sequence of Ds PKC gene to NCBI(Genbank No. JN625213). In the present paper, the Ds PKC gene open reading frame obtained by PCR was cloned into pGS-21 a vector and transformed into Escherichia coli to generate the fusion protein. Bioinformatics analysis revealed that DsPKC gene was a member of serine/threonine kinase with two conserved domains and highly conserved motifs. The Ds PKC was highly expressed upon induction with isopropyl-β-d-thiogalactoside(IPTG) at a final concentration of 0.2 mmol L~(-1) at 37℃. Under salt stress, the fusion protein Green Fluorescent Protein(GFP)-DsPKC was transferred from the cytoplasm to the cell membrane. The expression pattern of Ds PKC gene was analyzed using real-time quantitative PCR, and indicated that Ds PKC gene was up-regulated by 3.0 mol L~(-1) NaCl at 12 h, which was significantly higher than in control values(P 0.05). These results suggest that the Ds PKC gene plays an important role in response to salt stress in D. salina. 相似文献
Use of deep‐water sediments in submarine fans to reconstruct changing erosion onshore is based on the premise of relatively simple transport between source and sink. However, debate continues regarding the degree of sediment buffering and recycling in the sediment transport process. In this study, we investigate the origin of sediment in the Indus Submarine Canyon since the Last Glacial Maximum (LGM; ~20 ka) using zircon U‐Pb dates. Zircon grains in the submarine canyon are resolvably different from those at the river mouth, at least before 6.6 ka, implying a disconnection between the river mouth and the canyon up to that time. Sand may be stored near the river mouth as sea level rose, while finer‐grained sediment was directly transferred into deeper water. Since 1 ka the upper canyon has shown big and rapid provenance changes, most notably a sharp increase in erosion from Nanga Parbat, whose influence is minor in the modern river. Such rapid changes imply a lack of buffering in the recent past. The modern river contrasts with sediments in the canyon in terms of its zircon U‐Pb age populations and may be influenced by significant anthropogenic impact on the terrestrial drainage basin, especially damming. 相似文献