Dissolution in He 8 Sandstones, Sulige Gasfield, Ordos Basin: Origin, Distribution, and Effect on Reservoir Properties

2013 ◽  
Vol 807-809 ◽  
pp. 2257-2262
Author(s):  
Wen Ji Lin ◽  
Da Zhen Tang ◽  
Shu Tao
Keyword(s):  
Ordos Basin ◽  
Gas Production ◽  
Reservoir Properties ◽  
Delta Front ◽  
Delta Plain ◽  
Channel Deposits ◽  
Distributary Channel

Dissolution plays a dominant controlling role on reservoir properties in delta sandstone of the Permian He 8 Formation, Sulige gasfield. Dissolution forms intergranular dissolved pore and intragranular dissolved pore. Areas with high percentages of dissolved pores occur along delta-plain distributary channel and delta-front underwater distributary channel deposits. Due to dissolution, the porosity increased to 10-17% with permeability as high as 10md. Wells drilled through He 8 sandstones have high daily gas production of 4~6×104m3/d.

scholarly journals Sedimentología e icnología de un delta fluvio-dominado, Formación Lajas (Jurásico Medio), cuenca Neuquina, Argentina

2020 ◽  
Vol 47 (1) ◽  
pp. 179 ◽  
Author(s):  
Nerina Canale ◽  
Juan José Ponce ◽  
Noelia B. Carmona ◽  
Martín N. Parada ◽  
Daniel I. Drittanti
Keyword(s):  
Organic Matter ◽  
Particulate Organic Matter ◽  
Middle Jurassic ◽  
Trace Fossils ◽  
Delta Front ◽  
Deformation Structures ◽  
Low Diversity ◽  
Channel Deposits ◽  
Channel Systems ◽  
Distributary Channel

Sedimentologic and ichnologic analysis of the Middle Jurassic Lajas Formation in Bajada de Los Molles area allow recognizing upper offshore-lower shoreface deposits in transition to prodelta, delta front and interdistributary bay succesions. This system is classified as a river-dominated delta due to the presence of distributary channel deposits with huge amounts of particulate organic matter and low diversity and abundance of trace fossils. Hyperpycnites are common in the basal and upper part of the studied section, and form channel-levee and distributary-channel systems, integrated by massive sandstones and load deformation structures, or transitional and recurrent passages of tractive sedimentary structures with abundant particulate organic matter on the foresets. The greatest diversity and abundance of trace fossils are recognized in the upper offshore-lower shoreface deposits where Skolithos and Cruziana ichnofacies occur. Deltaic deposits show trace fossil associations with lower diversity and abundance than the fully marine ones, whereas the hyperpycnite deposits are either unbioturbated or show the lowest diversity and abundance of trace fossils, reflecting the most stressed conditions within the system.

scholarly journals Taphonomy of Isisfordia duncani specimens from the Lower Cretaceous (upper Albian) portion of the Winton Formation, Isisford, central-west Queensland

2018 ◽  
Vol 5 (3) ◽  
pp. 171651 ◽  
Author(s):  
Caitlin E. Syme ◽  
Steven W. Salisbury
Keyword(s):  
Brackish Water ◽  
Lower Cretaceous ◽  
Future Studies ◽  
Delta Plain ◽  
Fossil Material ◽  
Close Proximity ◽  
Crocodylus Porosus ◽  
Taphonomic Analysis ◽  
Channel Deposits ◽  
Distributary Channel

Taphonomic analysis of fossil material can benefit from including the results of actualistic decay experiments. This is crucial in determining the autochthony or allochthony of fossils of juvenile and adult Isisfordia duncani , a basal eusuchian from the Lower Cretaceous (upper Albian) distal-fluvial-deltaic lower Winton Formation near Isisford. The taphonomic characteristics of the I. duncani fossils were documented using a combination of traditional taphonomic analysis alongside already published actualistic decay data from juvenile Crocodylus porosus carcasses. We found that the I. duncani holotype, paratypes and referred specimens show little signs of weathering and no signs of abrasion. Disarticulated skeletal elements are often found in close proximity to the rest of the otherwise articulated skeleton. The isolated and disarticulated skeletal elements identified, commonly cranial, maxillary and mandibular elements, are typical of lag deposits. The holotype QM F36211 and paratype QM F34642 were classified as autochthonous, and the remaining I. duncani paratypes and referred specimens are parautochthonous. We propose that I. duncani inhabited upper and lower delta plains near the Eromanga Sea in life. Their carcasses were buried in sediment-laden floodwaters in delta plain overbank and distributary channel deposits. Future studies should refer to I. duncani as a brackish water tolerant species.

The Distribution Rules of Gas in Shan 2 Member in Yulin Area of Changqing Gas Field

2014 ◽  
Vol 962-965 ◽  
pp. 506-511
Author(s):  
Jing Chao
Keyword(s):  
Ordos Basin ◽  
Gas Production ◽  
Delta Front ◽  
Quartz Content ◽  
Gas Field ◽  
Good Relationship ◽  
Distribution Rules ◽  
Exploration And Production ◽  
Mouth Bar ◽  
Favorable Conditions

Yulin area of Changqing gas field in Ordos basin has the favorable conditions for gas accumulation in Shan 2 Member, which is the main productive layer to increase reserve and production. Based on the research of gas pool forming conditions, the distribution rules of gas in Shan 2 Member in Yulin area of Changqing gas field can be concluded: coals, swap dark mudstones and delta front sandbodies are well-developed vertically, the conditions of reservoir-forming combination for self-generation and self-preservation are processed; the sandbodies developed in submerged distributary channel and mouth bar microfacies of delta front have a high content of quartz, which have a good physical properties and a high gas production. There is a good relationship between the distribution of gas pools and the maturity of sandstone, the value 6 of maturity index (86% quartz content) can be used to delineate the zones of gas enrichment and productivity. This rule can guide the exploration and production of this area in next step.

Analysis on Basic Conditions and Main Control Factors of Accumulation in Eastern Area of Yishan Slope of Ordos Basin

2012 ◽  
Vol 524-527 ◽  
pp. 10-15
Author(s):  
Bao Hong Shi ◽  
Juan Wang ◽  
Yan Zhang
Keyword(s):  
Ordos Basin ◽  
Petroleum Reservoirs ◽  
Delta Front ◽  
Eastern Area ◽  
Delta Plain ◽  
Hydrocarbon Reservoir ◽  
Control Factors ◽  
Cap Rock ◽  
And Migration ◽  
Sand Bodies

The group of reservoir and cap-rock in Chang4+5 and Chang6 has good basic conditions of accumulation in eastern area of Yishan Slope of Ordos Basin, because it located up the high quality sources rocks (Chang7) and had a lot of hydrocarbon migrated from western areas. The reservoirs were the sand bodies formed in the distributary channels of delta plain and subaqueous distributary channels of delta front. The cap-rocks were the mudstones and compacted siltites formed in the floodplain and interdistributary areas.They composed lithologic traps. The types of petroleum reservoirs belong to lithologic hydrocarbon reservoir. The distribution of oil layers controlled by depositional microfacies and the excellent quality group of reservoir and cap-rock and migration conditions.

scholarly journals Sedimentological Influence on Physical Properties of a Tight Sandstone Reservoir: The Cretaceous Nenjiang Formation, Southern Songliao Basin, Northeast China

2021 ◽  
Vol 9 ◽  
Author(s):  
Jinkai Wang ◽  
Jialin Fu ◽  
Jieming Wang ◽  
Kai Zhao ◽  
Jinliang Zhang ◽  
...  
Keyword(s):  
Physical Properties ◽  
Songliao Basin ◽  
Physical Parameters ◽  
Tight Sandstone ◽  
Reservoir Properties ◽  
Delta Front ◽  
Sedimentary Process ◽  
Throat Radius ◽  
Mouth Bar ◽  
Distributary Channel

Abstract:The Nenjiang Formation, south of Songliao Basin, has many hydrocarbon bearing units, but currently the understanding of the distribution of viable reservoir sandstones is too limited to support a development strategy. Therefore, a detailed study on the sedimentary microfacies and reservoir properties has been completed in order to reduce uncertainty and improve subsurface predictions. Nine lithofacies and five lithofacies associations were identified supporting the development of a sedimentary model of a river-dominated delta front setting, which could be divided into four sedimentary environments: subaqueous distributary channel-fill, mouth bar, sand sheet, and interdistributary bay. The distribution sandbodies extend to the south in a tongue-like form, and they thin and pinch out. Finally, the influence of sedimentary process on properties was assessed by establishing the correlation between microfacies and reservoir physical parameters, such as porosity, permeability, pore radius, throat radius, and clay minerals. It is revealed that the correspondence between reservoir physical properties and microfacies types is strong; the physical properties of the subaqueous distributary channel and mouth bar are the best.

Comparative analysis of production potential in Bulla-deniz and Umid gas-condensate fields

2020 ◽  
pp. 21-26
Author(s):  
E.H. Ahmadov ◽  
Keyword(s):  
Oil And Gas ◽  
Reduction Rate ◽  
Chemical Properties ◽  
Gas Production ◽  
Layer System ◽  
Reservoir Properties ◽  
Technical Parameters ◽  
Recovery Curves ◽  
Well Model ◽  
Drilling Technology

The paper studies the reduction rate of gas production in the wells of Bulla-deniz field drilled to VIII horizon. With this purpose, geological (reservoir properties, oil-gas saturation, net thickness, formation pressure and temperature, formation heterogeneity, multi-layer system, tectonic faults, physical-chemical properties of oil and gas etc.) and technological (well structure, measuring and transportation system, well operation regime, drilling technology etc.) conditions of formation were analyzed and the well model of VII and VIII horizons of Bulla-deniz field using these geological and technical parameters developed as well. For the estimation of impact of geological and technical aspects on production, sensitivity analysis was carried out on the models. The suggestions for elaboration of uncertainty of geological and technical parameters affecting production dynamics were developed. To reveal the reasons for production differences of the wells, it was proposed to install borehole manometers, to obtain the data on pressure recovery curves, drainage area, skin-effect impact, permeability and to develop a study plan of bottomhole zone with acid.

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