scholarly journals Impacts of the Base-Level Cycle on Pore Structure of Mouth Bar Sand Bars: A Case Study of the Paleogene Kongdian Formation, Bohai Bay Basin, China

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2617 ◽  
Author(s):  
Xixin Wang ◽  
Jiagen Hou ◽  
Yuming Liu ◽  
Ling Ji ◽  
Jian Sun ◽  
...  
Keyword(s):  
Pore Structure ◽  
Early Stage ◽  
Mean Value ◽  
Bohai Bay ◽  
Base Level ◽  
Sand Body ◽  
Structure Heterogeneity ◽  
Mouth Bar ◽  
Hydrocarbon Distribution ◽  
Sand Bodies

The pore structure of rocks can affect fluid migration and the remaining hydrocarbon distribution. To understand the impacts of the base-level cycle on the pore structure of mouth bar sand bodies in a continental rift lacustrine basin, the pore structure of the mouth bar sand bodies in the ZVC (ZV4 + ZV5) of the Guan195 area was studied using pressure-controlled mercury injection (PMI), casting sheet image and scanning electron microscopy (SEM). The results show that three types of pores exist in ZVC, including intergranular pores, dissolution pores, and micro fractures. The porosity is generally between 1.57% and 44.6%, with a mean value of 19.05%. The permeability is between 0.06 μm2 and 3611 μm2, with a mean value of 137.56 μm2. The pore structure heterogeneity of a single mouth bar sand body in the early stage of the falling period of short-term base-level is stronger than that in the late stage. During the falling process of the middle-term base level, the pore structure heterogeneity of a late single mouth bar sand body is weaker than that of an early single mouth bar sand body. In the long-term base-level cycle, the pore structure heterogeneity of mouth bar sand bodies becomes weaker with the falling of the base-level.

Integrated Solutions for the Redevelopment Plan of Offshore Mature-Oilfield

2021 ◽  
Author(s):  
Hongfu Shi ◽  
Yingxian Liu ◽  
Lifu Jiang ◽  
Jingding Zheng ◽  
Liqin Gan
Keyword(s):  
High Water ◽  
Bohai Bay ◽  
Sand Body ◽  
Well Pattern ◽  
Open Hole ◽  
Average Water ◽  
High Water Cut ◽  
Water Cut ◽  
Stream Lines ◽  
Sand Bodies

Abstract Abundant faults, long oil-bearing intervals (up to 500m), and diverse fluids including conventional oil and heavy oil, result in P oilfield became one of the most complex oil fields in the Bohai Bay. The main characters ofinitial development plan are directional well with commingle production, open hole completion, large draw down, high oil production rate, and reverse nine-point well pattern. At present, the oilfield has entered a stage of high water cut, with average water cut more than 85%. What can we do next, decommissioning or rebirthing? An integrated solution was proposed to redevelop the oilfield which focus on the layers’ subdivision, the fine description of the sand body,a large number of horizontal wells on the top of the water-flooded layer are used to tap the potential, increase the water injector to transform the stream lines and rebuild the reservoir pressure, and search for potential sand bodies to increase reserves.

scholarly journals Sedimentary Facies of the Chang 2 Member of Yanchang Formation in Area A of Northern Shaanxi

2021 ◽  
Vol 290 ◽  
pp. 02012
Author(s):  
Yingzhi Liu ◽  
Yanyan Liu ◽  
Ying Chen ◽  
Shasha Yang ◽  
Bowang Wang
Keyword(s):  
Sedimentary Facies ◽  
Stratigraphic Correlation ◽  
Sequence Stratigraphic ◽  
Delta Plain ◽  
Base Level ◽  
Sand Body ◽  
Single Well ◽  
Northern Shaanxi ◽  
Core Description ◽  
Sand Bodies

In order to promote the rolling exploration and development of oil reservoirs in northern Shaanxi, a fine study of sedimentary facies in area A has been carried out. Using core and logging data, on the basis of identifying different levels of sequence interfaces and lake flooding, the Chang 2 Member in Area A was divided into two base level cycles, and a high-resolution sequence stratigraphic correlation was established. On the basis of core description, the analysis of single-well sedimentary facies, continuous-well sedimentary facies and planar sedimentary facies are carried out. It is believed that the Chang 2 member of the study area is a delta plain deposit, dominated by distributary channels, inter-distributary depressions, and natural dike microfacies. There are two to three main rivers in the study area. Both the vertical and the plane show that the length of Chang 22 sand bodies is more developed than the length of Chang 21 sand bodies. Among the three small layers of Chang 22, Chang 221 sand body is relatively well developed, and the channel width and thickness are large, making it the most favorable reservoir.

DEPOSITIONAL ENVIRONMENTS AND HYDROCARBON POTENTIAL OF THE EVERGREEN FORMATION, ATP 145P, SURAT BASIN, QUEENSLAND

1986 ◽  
Vol 26 (1) ◽  
pp. 156
Author(s):  
V. Golin ◽  
M. Smyth
Keyword(s):  
Depositional Environments ◽  
Alluvial Fan ◽  
Source Rocks ◽  
Small Stream ◽  
Fine Grained ◽  
Base Level ◽  
Mouth Bar ◽  
Dynamic Seal ◽  
Sand Bodies ◽  
Petrographic Study

Hydrocarbon discoveries in the Jurassic Evergreen Formation along the western shelf of the Surat Basin lie in a northwest-trending structurally controlled belt adjacent to Bridge-operated ATP 145P. Shows and commercial accumulations are generally associated with specific sand/shale ratios, which influence source, reservoir, and seal effectiveness. Proximity to basement and early faults are other favourable factors.Four distinct log facies were calibrated against cuttings and core and interpreted genetically. Small, stream-dominated alluvial-fan systems extended from low escarpments in the west, but were reworked along their basinward margins prior to being overstepped by aggradational, onlapping distal sediments. Prominent east-northeast-trending belts occupied by mixed-load fluvial channel systems terminated along a temporary shoreline of coalescing wave-dominated deltas. This deltaic-shore-zone sand belt was truncated by fluvial-distributary channels during the ensuing regression to another still-stand some 25 km farther east. Shoreline positions fluctuated locally in response to competition between rate of sediment influx and the gradually rising base level; but the net effect was regional transgression, with reworked shorezone/nearshore sheetsands grading up into silty shales of the shallow epeiric platform.On the basis of a petrographic study the highest source potential for the Evergreen Formation in ATP 145P is around Spring Grove 1 well. A band of high source potential lies parallel to the deltaic shoreline, in a generally north-south direction. The highest source potential of the Triassic Moolayember Formation lies around Spring Grove 1 and in a north-south trending arc through Roswin 1 and Sirrah 4. The source potential of the combined Triassic Snake Creek Member, Showgrounds and (Permian) Kianga formations is highest around Roswin 1. In the area of Roswin 1 all formations studied show a high potential as source rocks for hydrocarbons. Based on the available data, the Triassic Moolayember Formation appears to be the only formation common to all producing wells with a high source potential in each well.Zones of thick, porous sands are not very prospective for hydrocarbons in the study area, possibly because of ineffective seal. True shales are rare in the Evergreen Formation. The dominant fine-grained lithology is silt-stone, which by itself provides a leaky or dynamic seal at best. Thin, reworked delta mouth bar and splay sands with thick seals may offer the best reservoir objectives. Known hydrocarbons generally occur in structural-strati-graphic traps with the structural component caused by compaction and subsequent draping over basement topography, and the stratigraphic component arising from the lenticularity of the fluvio-deltaic sand bodies.

scholarly journals Serum surfactant protein D in COVID-19 is elevated and correlated with disease severity

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ming Tong ◽  
Ying Xiong ◽  
Chen Zhu ◽  
Hong Xu ◽  
Qing Zheng ◽  
...  
Keyword(s):  
Acute Phase ◽  
Early Stage ◽  
Recovery Period ◽  
Serum Levels ◽  
Surfactant Protein ◽  
Mean Value ◽  
Multivariate Logistic Regression Model ◽  
Surfactant Protein D ◽  
Multivariate Logistic Regression ◽  
Roc Curve Analysis

Abstract Background The serum surfactant protein D (SP-D) level is suggested to be a useful biomarker for acute lung injuries and acute respiratory distress syndrome. Whether the serum SP-D level could identify the severity of coronavirus disease 2019 (COVID-19) in the early stage has not been elucidated. Methods We performed an observational study on 39 laboratory-confirmed COVID-19 patients from The Fourth People’s Hospital of Yiyang, Hunan, China. Receiver operating characteristic (ROC) curve analysis, correlation analysis, and multivariate logistic regression model analysis were performed. Results In the acute phase, the serum levels of SP-D were elevated significantly in severe COVID-19 patients than in mild cases (mean value ± standard deviation (SD), 449.7 ± 125.8 vs 245.9 ± 90.0 ng/mL, P<0.001), while the serum levels of SP-D in the recovery period were decreased dramatically than that in the acute phase (mean value ± SD, 129.5 ± 51.7 vs 292.9 ± 130.7 ng/ml, P<0.001), and so were for the stratified patients. The chest CT imaging scores were considerably higher in the severe group compared with those in the mild group (median value, 10.0 vs 9.0, P = 0.011), while markedly lower in the recovery period than those in the acute phase (median value, 2.0 vs 9.0, P<0.001), and so were for the stratified patients. ROC curve analysis revealed that areas under the curve of lymphocyte counts (LYM), C-reaction protein (CRP), erythrocyte sedimentation rate (ESR), interleukin-6 (IL-6), and SP-D for severe COVID-19 were 0.719, 0.833, 0.817, 0.837, and 0.922, respectively. Correlation analysis showed that the SP-D levels were negatively correlated with LYM (r = − 0.320, P = 0.047), while positively correlated with CRP (r = 0.658, P<0.001), IL-6 (r = 0.471, P = 0.002), the duration of nucleic acid of throat swab turning negative (r = 0.668, P<0.001), chest CT imaging score on admission (r = 0.695, P<0.001) and length of stay (r = 0.420, P = 0.008). Multivariate logistic regression model analysis showed that age (P = 0.041, OR = 1.093) and SP-D (P = 0.008, OR = 1.018) were risk factors for severe COVID-19. Conclusions Elevated serum SP-D level was a potential biomarker for the severity of COVID-19; this may be useful in identifying patients whose condition worsens at an early stage.

Enhancement of reflection and backscattering components by plane wave imaging for estimation of surface roughness

2021 ◽  
Author(s):  
Kazuhiro Tochigi ◽  
Ryo Nagaoka ◽  
Jens Erik Wilhjelm ◽  
Hideyuki Hasegawa
Keyword(s):  
Surface Roughness ◽  
Plane Wave ◽  
Arterial Wall ◽  
Early Stage ◽  
Mean Value ◽  
Luminal Surface ◽  
Ultrasonic Echo ◽  
Wave Imaging ◽  
The Mean ◽  
Reflection Component

Abstract In the early stage of atherosclerosis, the luminal surface of the arterial wall becomes rough. Methods for distinguishing between the reflected and backscattered components in the ultrasonic echo from the arterial wall has the potential to be used as a method for assessment of the roughness of the arterial wall. In this study, we proposed a method to distinguish between the reflected and backscattered components using a technique based on plane wave compounding. This method was evaluated by experiments using planar phantoms with rough surfaces made of polyurethane rubber. The coefficient of variation calculated from the mean value of the reflection component and the standard deviation of the backscattering component was proportional to the roughness of the rubber phantom. This result shows the potential usefulness of this method for analyzing surface roughness of the arterial wall.

scholarly journals Distribution and controls of petroliferous plays in subtle traps within a Paleogene lacustrine sequence stratigraphic framework, Dongying Depression, Bohai Bay Basin, Eastern China

2019 ◽  
Vol 17 (1) ◽  
pp. 1-22 ◽  
Author(s):  
Ji-Chang Zhu ◽  
Cai-Neng Zou ◽  
You-Liang Feng ◽  
Shu Jiang ◽  
Wei-An Wu ◽  
...  
Keyword(s):  
Eastern China ◽  
Source Rocks ◽  
Normal Faults ◽  
Dynamic Factor ◽  
Bohai Bay ◽  
Sequence Stratigraphic ◽  
Dongying Depression ◽  
Stratigraphic Framework ◽  
Incised Channel ◽  
Sand Bodies

AbstractThe characteristics of petroliferous plays in subtle traps within a sequence stratigraphic framework in the Dongying Depression are investigated in this study. Sand bodies within lowstand systems tracts (LSTs) of sequences, comprising incised-channel fills, sublacustrine fans, deltas in LSTs, controlled by syndepositional normal faults, and sand bodies within transgressive systems tracts (TSTs) to early highstand systems tracts (HSTs), consisting of beach bars, and turbidites, controlled by the prodelta slope, paleorelief, and syndepositional normal faults, are good subtle reservoirs. Mudstones and shale of deep lake subfacies in TSTs to early HSTs of sequences are source and cap rocks. Abnormal overpressure is the dominant dynamic factor for hydrocarbon migration from source rock to the subtle traps. Normal faults, sand bodies, and unconformities function as conduit systems. Sand bodies distributed in the abnormal overpressure source rocks within LSTs to early HSTs are petroliferous plays in lithologic traps. The petroliferous plays in stratigraphic traps are controlled by unconformities at margins of the Depression.

scholarly journals Soft-sediment Deformation Structures and Sand Body Architecture in the Chang 6 Oil Member of the Upper Triassic Yanchang Formation, Southwestern Ordos Basin, China

2019 ◽  
Vol 23 (2) ◽  
pp. 119-126 ◽  
Author(s):  
Qingshao Liang ◽  
Jingchun Tian ◽  
Feng Wang ◽  
Xiang Zhang
Keyword(s):  
Ordos Basin ◽  
Upper Triassic ◽  
Seismic Events ◽  
Soft Sediment ◽  
Delta Front ◽  
Yanchang Formation ◽  
Sand Body ◽  
Sediment Deformation ◽  
The Ordos Basin ◽  
Sand Bodies

Soft-sediment deformation (SSD) structures of the Upper Triassic Yanchang Formation are laterally widespread in the Ordos Basin. In the Huachi-Qingyang (H-Q) area of the Ordos Basin, the Chang6 oil member of the Upper Triassic Yanchang Formation is among the most significant Mesozoic oil-bearing strata. It is characterized by the development of reservoir sand bodies. During the depositional evolution of the Chang6 oil member, SSD structures induced by paleo-seismic events developed in the H-Q area in the middle of the basin. The SSD structures developed in the sand bodies of the Chang6 oil member are mainly ball-and-pillow structures, fold structures, sand dikes, irregular convolute stratifications and synsedimentary faults. The architecture of the sand bodies resulted from paleo-seismic events and gravity slumping and mainly include two types of structures: 1) SSD structures driven by paleo-seismic events with normal sedimentation (delta front sand body) (SN-SSD) and 2) SSD structures driven by paleo-seismic events with turbidites (formed by delta-front slumping and re-distribution due to seismic action) (ST-SSD). As a consequence, genetic models of the sand bodies formed by different sedimentation processes are established.

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