scholarly journals Causes of Oil Accumulation of Isolated Bars in Lacustrine Delta

Energies ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1489
Author(s):  
Panpan Chen ◽  
Cunlei Li ◽  
Jinliang Zhang ◽  
Shengrong Li ◽  
Guiyang Ma ◽  
...  
Keyword(s):  
Source Rocks ◽  
Distribution Model ◽  
Lake Basin ◽  
Hydrocarbon Accumulation ◽  
Delta Front ◽  
Oil Accumulation ◽  
Body Distribution ◽  
Storm Waves ◽  
Sand Body ◽  
Sand Bodies

After over 20 years of development in Daqingzijiang Oilfield, isolated sand bodies under the delta front and pro-delta in the Qingshankou Formation(qn)have become important oil and gas reservoir bodies. However, the cause for large amounts of isolated bar sand bodies in the lake-basin delta sediment system has not been reported in China. This article, through core observation, reveals plenty of evidence that there storm waves once existed. Combined with paleogeography and hydrodynamic force analysis, it describes the transformation effect of waves on delta sand bodies and on the formation mechanism of bar sand bodies. Based on a study on paleogeomorphology and the statistics of sand body distribution, we consider ‘Storm waves conveying sand’ and ‘landform controlling sand’ as the cause and distribution model of the delta’s isolated bar sand body formation. We also think that the superposition of multiple bar sand bodies is the direct cause of the strong anisotropy in reservoirs and the complex relationship between oil and water in reservoirs. Most of these sand bodies have formed into lenticular lithologic hydrocarbon accumulations. On the basis of this integrated study on hydrocarbon accumulation, we set up an accumulation model of lenticular hydrocarbon accumulation involving the variables ‘Surrounded by source rocks to generate hydrocarbon’, ‘Driven by pressure difference’, ‘Migration through multi pathways’ and ‘Accumulation by filtering water’.

Study on the hydrocarbon accumulation models of the upper Es3 in the gentle slope belt of Chexi Depression

2020 ◽  
Author(s):  
Shan Zhao ◽  
Hua Liu
Keyword(s):  
Oil And Gas ◽  
Controlling Factors ◽  
Source Rocks ◽  
Hydrocarbon Accumulation ◽  
Gas Reservoir ◽  
Sand Body ◽  
Main Controlling Factors ◽  
Two Stages ◽  
Oil And Gas Reservoir ◽  
Sand Bodies

<p>Based on the analysis of hydrocarbon source, reservoir forming period, composition and classification of transportation system, and the reasons of failure well in Chexi Depression of Bohai Bay Basin，Two types of hydrocarbon accumulation models in gentle slope belt of Chexi area are established and the main controlling factors of hydrocarbon accumulation are defined. There are three sets of source rocks（Es1、middle and lover submember of Es3、Es4）in Chexi area, the different strata of source rocks have great differences in the Pr/Ph and the content of gammacerane. It has been found that the crude oil of Es3 has a good geochemical correspondence with the middle and lower of Es3 source rocks, and has the characteristics of near source accumulation. The hydrocarbon accumulation in the study area exists in the sedimentary period of the Dongying formation and the sedimentary period of the Guantao formation to the present two stages, which is dominated by late filling. There are two stages of oil and gas filling in the inner and middle belts, and only late stage hydrocarbon filling in the outer slope belt. The hydrocarbon transportation system is mainly composed of faults and sand bodies. The effective source rocks in the middle and lover submember of Es3 are connected with the upper reservoir of Es3 in a small area, which can be directly migrated to the upper sandstone reservoir of Es3 to form lithologic oil and gas reservoir. However, most of the oil and gas in the upper Es3 reservoir need to be vertically migrated by means of oil source fault, and then through the contact of sand bodies such as main channel and fan body, the main oil and gas reservoir will gradually move up with the distance from the source rock. The area with direct contact source reservoir configuration relationship is a "sand body lateral migration" reservoir formation mode, and the main controlling factors of reservoir formation are sand body connectivity and reservoir porosity and permeability. The source reservoir configuration area with fault connection type is a "fault sand combination T-type migration" reservoir forming mode, and the main controlling factors of reservoir forming are migration convergence facies (structural ridge and cross-section ridge).The area of passive reservoir contact is "fault sand combination step migration" reservoir forming mode, and the main controlling factors of reservoir forming are migration convergence facies (structural ridge) and lateral sealing of faults in preservation conditions.</p><p>Key words: Chexi Depression; Source of hydrocarbon; Accumulation period; Fault sand transport combination; Reservoir forming mode</p>

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.

The Application of Facies Modeling Combination of Well Data and Seismic Data in G25-12 Block

2015 ◽  
Vol 733 ◽  
pp. 92-95
Author(s):  
Jia Hui Wang ◽  
Hong Sheng Lv
Keyword(s):  
Sedimentary Facies ◽  
Distribution Law ◽  
Skeleton Model ◽  
Facies Model ◽  
Body Distribution ◽  
Sand Body ◽  
Geological Conditions ◽  
Single Well ◽  
Well Data ◽  
Sand Bodies

The main purpose of lithofacies modeling is to get the actual reservoir lithofacies skeleton model which is maximum approximation of the underground reservoir. The facies model can effectively solve the problem of predicting sand bodies between wells. At the same time, we still use the stochastic modeling method to build the facies model of unconstrained single well simulation and sedimentary facies controlled constrained simulation. We elected the model which is most consistent to the actual geological conditions, providing theoretical guidance for characterizing the interwell sand body distribution law and improving the accuracy of predicting sand bodies between wells, laiding the foundation for further exploration and development of oil reservoir.

scholarly journals Prediction of channel sandbody distribution in the lower section of Sifangtai Formation at the southern end of Chang Placanticline in Songliao Basin

2021 ◽  
Vol 300 ◽  
pp. 02003
Author(s):  
Wenping Zhu ◽  
Axiang Sun ◽  
Xiaowen Liu ◽  
Shangming Shi ◽  
Huabin Wei
Keyword(s):  
Songliao Basin ◽  
Seismic Facies ◽  
Lower Section ◽  
Root Mean Square Amplitude ◽  
Body Distribution ◽  
Sand Body ◽  
Wide Range ◽  
Seismic Facies Analysis ◽  
Two Phases ◽  
Sand Bodies

The channel sand bodies in the lower section of the Sifangtai Formation in the Songliao Basin are rich in uranium resources. The development of channel sand body distribution prediction is of great significance for guiding the exploration of sandstone-type uranium deposits. In this study, the wave-indicated inversion technology was used to predict the thickness of the sand body, the root mean square amplitude attribute was used to identify the plane shape of the river channel, and the seismic facies analysis and tracking technology of the section was used to identify the channel period and finely describe the channel distribution. The results show that there are two stages of channel sand bodies in the lower part of Sifangtai Formation, and the sand bodies are distributed in a wide range. The maximum thickness of single stage sand bodies is about 15m, with an average of 8 meters. The thickness of the sand body where the two phases of the river are superimposed is the largest, up to 28m, which is a favorable ore-bearing location revealed by current exploration.

scholarly journals Application of seismic sedimentology to the western slope of northern Songliao basin

2021 ◽  
Vol 236 ◽  
pp. 03014
Author(s):  
Ji Xianwei
Keyword(s):  
Songliao Basin ◽  
Quantitative Prediction ◽  
Bottom Surface ◽  
Western Slope ◽  
Delta Front ◽  
Reservoir Prediction ◽  
Seismic Section ◽  
Sand Body ◽  
Seismic Sedimentology ◽  
Sand Bodies

During the sedimentary period of Saertu reservoir on the western slope of the northern Songliao basin, delta front and shore-shallow lake subfacies are mainly developed, which have the characteristics of few sandstone layers and thin single layer thickness. The lithology of thin layer or thin interlayer can not be distinguished clearly by seismic response on conventional seismic section, and it is difficult to identify them. Geophysical response characteristics of channel sand bodies are defined by well-seismic combination. Under the guidance of seismic sedimentology, the qualitative and quantitative prediction of channel sand bodies is carried out by using 90°-phase conversion, stratal slicing and waveform indication inversion techniques. The results show that the seismic reflection axis is symmetrical with respect to the top and bottom surface of sandstone, and the channel sand body has obvious characteristics and completely corresponds to wave peak reflection. The channel bodies of S1 and S23 reservoir formation are separated respectively into two stages by using the amplitude attributes of stratal slices, and the coincidence rate of reservoir prediction to wells is 78%~84%, with an average of 79.7%. The waveform indicator inversion technique is used to predict the channel sand body thickness of the four stages, and the error of sand body thickness to well is 0~1.6m, with an average of 0.32m.

scholarly journals Analysis of Reservoir Architecture of Shallow-water Delta Front Based on Process—A Case of S2L410 in Southern 79 Block in Wennan Oilfield

2017 ◽  
Vol 4 (1) ◽  
pp. 96
Author(s):  
Le Chen ◽  
Zhipeng Lin ◽  
Taiju Yin ◽  
Zhongchao Li ◽  
Chunsheng Shen ◽  
...  
Keyword(s):  
Horizontal Wells ◽  
High Water ◽  
Data Logging ◽  
Delta Front ◽  
Reservoir Architecture ◽  
Body Distribution ◽  
Sand Body ◽  
Geological Research ◽  
Internal Architecture ◽  
Distributary Channel

The sand body distribution is relatively limited in this block, the lens-shaped sandbodies are more developed, the change of intergranular sandbody is fast and the internal architecture of the sand body is complex, which results in the difficulties of the arrangement of horizontal wells in the study area and the tapping of remaining oil in high water reservoirs. In this paper, taking an example of S2L410 sandbodies in Wen 79 Southern Block, rich drilling data, core data, logging data and geological research results accumulated over many years in Wennan Oilfield were applied to discuss the anatomical method of the reservoir architecture unit in the underwater distributary channel in the shallow delta front, the hierarchy of the internal architecture of the reservoir and the anatomy of the single sand body. On the basis of this, the sequence of the underwater distributary channel in the composite channel is determined by the cross section and the source profile. Under the guidance of the sedimentology principle, the formation process of the underwater distributary channel is restored and the evolution process of underwater distributary channel is recovered.

Predict Channel Sand Body Distribution Characteristics of South Eighth District Based on RMS Amplitude Attributes & Frequency Division

2013 ◽  
Vol 734-737 ◽  
pp. 404-407 ◽  
Author(s):  
Yu Shuang Hu ◽  
Si Miao Zhu
Keyword(s):  
Seismic Data ◽  
Physical Property ◽  
Sedimentary Facies ◽  
Distribution Area ◽  
Frequency Division ◽  
Root Mean Square Amplitude ◽  
Seismic Attribute ◽  
Body Distribution ◽  
Attribute Analysis ◽  
Sand Body

A big tendency in oil industry is underestimating the heterogeneity of the reservoir and overestimating the connectivity, which results in overly optimistic estimates of the capacity. With the development of seismic attributes, we could pick up hidden reservoir lithology and physical property information from the actual seismic data, strengthen seismic data application in actual work, to ensure the objectivity of the results. In this paper, the channel sand body distribution in south eighth district of oilfield Saertu is predicted through seismic data root-mean-square amplitude and frequency division to identify sand body boundaries, predict the distribution area channel sand body characteristics successfully, which consistent with the sedimentary facies distribution. The result proves that seismic attribute analysis has good practicability in channel sand body prediction and sedimentary facies description.

scholarly journals Low Temperature Illitization through Illite-Dioctahedral Vermiculite Mixed Layers in a Tropical Saline Lake Rich in Hydrothermal Fluids (Sochagota Lake, Colombia)

Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 523
Author(s):  
Gabriel Ricardo Cifuentes ◽  
Juan Jiménez-Millán ◽  
Claudia Patricia Quevedo ◽  
Fernando Nieto ◽  
Javier Cuadros ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Organic Matter ◽  
Low Temperature ◽  
High Salinity ◽  
Source Rocks ◽  
Temperate Climate ◽  
Lake Basin ◽  
X Ray ◽  
Saline Waters ◽  
Mixed Layers

In this investigation, we showed that high salinity promoted by hydrothermal inputs, reducing conditions of sediments with high content in organic matter, and the occurrence of an appropriate clay mineral precursor provide a suitable framework for low-temperature illitization processes. We studied the sedimentary illitization process that occurs in carbonaceous sediments from a lake with saline waters (Sochagota Lake, Colombia) located at a tropical latitude. Water isotopic composition suggests that high salinity was produced by hydrothermal contribution. Materials accumulated in the Sochagota Lake’s southern entrance are organic matter-poor sediments that contain detrital kaolinite and quartz. On the other hand, materials formed at the central segment and near the lake exit (north portion) are enriched in organic matter and characterized by the crystallization of Fe-sulfides. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), and energy dispersive X-ray spectrometry (EDX) data allowed for the identification of illite and illite-dioctahedral vermiculite mixed layers (I-DV), which are absent in the southern sediments. High humidity and temperate climate caused the formation of small-sized metastable intermediates of I-DV particles by the weathering of the source rocks in the Sochagota Lake Basin. These particles were deposited in the low-energy lake environments (middle and north part). The interaction of these sediments enriched in organic matter with the saline waters of the lake enriched in hydrothermal K caused a reducing environment that favored Fe mobilization processes and its incorporation to I-DV mixed layers that acted as mineral precursor for fast low temperature illitization, revealing that in geothermal areas clays in lakes favor a hydrothermal K uptake.

Controlling Factors of Hydrocarbon Accumulation in Talaha-Changjiaweizi Area

2013 ◽  
Vol 734-737 ◽  
pp. 1175-1178
Author(s):  
Hong Qi Yuan ◽  
Ying Hua Yu ◽  
Fang Liu
Keyword(s):  
Physical Properties ◽  
Oil And Gas ◽  
Controlling Factors ◽  
Source Rocks ◽  
Hydrocarbon Accumulation ◽  
Gas Migration ◽  
Main Controlling Factors ◽  
Sedimentary Microfacies ◽  
Plane Distribution ◽  
Distributary Channel

Based on the analysis of the relationships between the conditions of structures, sedimentations, source rocks, cap rocks, faults, oil and gas migration passages and traps and hydrocarbon accumulation, the controlling factors of hydrocarbon accumulation and distribution was studied in Talaha-changjiaweizi area. It is held that the source rocks control the hydrocarbon vertical distribution, the drainage capabilities control the hydrocarbon plane distribution, fracture belts control the hydrocarbon accumulation of Talaha syncline, underwater distributary channel is a favorable accumulation environment and reservoir physical properties control the oil and water distributions. Therefore, it is concluded that source rocks, fracture belts, sedimentary microfacies and reservoir physical properties are the main controlling factors of hydrocarbon accumulation and distribution in Talaha-changjiaweizi area.

Sign in / Sign up

Export Citation Format

Share Document