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>

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.

Study on the Application of the EPSTM Image Based Post-Stack Spectrum Imaging to the Identification of the Riverway Sand Bodies in Fuyang Oil Layer of Songliao Basin

2013 ◽  
Vol 443 ◽  
pp. 668-674
Author(s):  
Chun Rui Chen ◽  
Xin Rong Zhang ◽  
Jin Ping Liu ◽  
Shi Fang
Keyword(s):  
Relative Error ◽  
Oil And Gas ◽  
Statistical Error ◽  
Oil Field ◽  
Gas Reservoir ◽  
Sand Body ◽  
Spectrum Imaging ◽  
Anisotropic Reservoirs ◽  
Oil And Gas Reservoir ◽  
Sand Bodies

The later-period structure of Fuyang oil layer is complex and its reservoir is mostly composed by the sand bodies of riverways. The oil and gas reservoir features obvious concealment, and also is difficult to identify. To accurately describe the reservoir, a post-stack spectrum imaging was made for the identification of the riverway sand bodies in Fuyang oil layer using EPSTM image in the study area. The statistical error of the riverway sand body identification result using post-stack spectrum imaging was small if the sandstone thickness was greater than 3m. Seen from logging wells geological verification, the riverway identification fit rate was 81.6% on average, the microfacies type identification fit rate was 75%, and the microfacies types identification fit rate of the sandstone thicker than 3m was 80%. Using the nonlinear algorithm of the MDI software, the lithologic prediction was implemented based on the sand group as the unit, and the average prediction fit rate of the sandstone thicker than 3m reached 90% according to the standard relative error less than 20%. Therefore, the post-stack spectrum imaging can exert a significant effect for the anisotropic reservoirs of complex later-period structure, thin sand body, and complex changes, and can meet the needs of the oil field exploration and development to some extent.

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’.

Main Controlling Factors of Hydrocarbon Accumulation at Different Phases: A Study on the Main Fault Depression Zones of Central H Basin

2015 ◽  
Vol 733 ◽  
pp. 39-42
Author(s):  
Zi Li Fan
Keyword(s):  
Early Phase ◽  
Oil And Gas ◽  
Late Phase ◽  
Controlling Factors ◽  
Source Rocks ◽  
Delta Front ◽  
Oil And Gas Exploration ◽  
Gas Accumulation ◽  
Main Controlling Factors ◽  
Main Fault

To understand the oil and gas accumulation rules and main controlling factors of H Basin at different phases, approaches such as reservoir dissection and analysis on the spatial allocation of reservoir accumulation conditions are adopted to divide the reservoir of the main fault depression zones of central H Basin into early and late phases. The widely-spread oil and gas at early phase are obviously more than that of the late phase. The main controlling factors of reservoir accumulation at early phase include source rocks area, antithetic faults - tilted upheavals and sand body of fan delta front subfacies while that of the late phase include sources rocks area, inverted structure and long-term developed fractures. The achievement of the study expounded in this paper is significantly important to correctly understand the oil and gas accumulation rules of complicated faulted-block fields and guide the oil and gas exploration activities.

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