Characteristic of Tuwayil Formation and New Insight into its Contribution in Middle Cretaceous Petroleum System, Western UAE

2021 ◽  
Author(s):  
Dengyi Xiao ◽  
Mingsheng Lv ◽  
Guangcheng Hu ◽  
Wenyuan Tian ◽  
Li Wang ◽  
...  

Abstract In Western UAE, the Middle Cretaceous petroleum system is composed of Shilaif source, Mishrif/Tuwayil reservoir and Tuwayil/Ruwaydha seal. Oil is discovered in Tuwayil sandstone in DH and NN fields. Well correlation of Tuwayil siliciclastic interval shows high heterogeneity and rapid lithology varies. Currently, a few general studies about Tuwayil sandstone was published. However, detailed sedimentary facies, reservoir characteristics and accumulation mechanism about Tuwayil are ambiguous. Limitation on these aspects prohibits enlarging exploration activity of Tuwayil and makes barriers to deepen understanding of the whole K2 PS. To enhance understanding on Tuwayil formation, well data in DH, NN fields and adjacent area was integrated. Dedicated single well analysis, well correlation and petrophysics study were carried out. Cores were observed and laboratory outcomes including TS, SEM, RCA, MICP, XRD were adopted into this study. Furthermore, we have also utilized 2D&3D seismic to illustrate the spatial distribution of Tuwayil siliciclastic setting and interior sediment pattern. Basically, the Tuwayil sand-shale interval represents the infilling of Mishrif/Shilaif intrashelf basin and mainly deposits in the tidal flat-delta facies. The epi-continental clast is sourced from the Arabian shield and transferred from west to east. In Western UAE, the Tuwayil depocenter located in DH field, where 4-5 sand layers deposit with net pay of 30-40ft. In NN field, only one sand layer develops with net pay about 4-6ft. Through deposition cycles identification and seismic reflection observation, two sand groups could be recognized in this interval. The lower group is constrained in the depocenter and influenced by the paleo-geomorphology background. The upper group overpassed the former set and pinched out around north of NN. The Mishrif/Shilaif slope area is another potential belt to enlarge Tuwayil discovery, where stratigraphic onlap could be observed and it probably represents the sand pinch-out in lower sand group. For the K2 PS, previous study believed the shale between Tuwayil sand and Mishrif separate these two reservoirs and works as cap rock for Mishrif grainstone. This study suggests that this shale is too thin and not continuous enough to hold the hydrocarbon in Mishrif. On that note, Tuwayil sand and Mishrif belong to the same petroleum system in NN and may have the same OWC. In the NN field, it is quite crucial to consider the extension of Tuwayil sand during evaluating the stratigraphic prospect of Mishrif because the hydrocarbon is mostly likely charged Tuwayil sand first and then gets into underlain Mishrif. This study provides updates and understandings on sedimentary facies, depositional pattern, hydrocarbon accumulation mechanism, reservoir extension and potential identification of Tuwayil formation, which has inspiring implications for the whole K2 PS and could also de-risk the further exploration activity in Western UAE.

2015 ◽  
Vol 733 ◽  
pp. 92-95
Author(s):  
Jia Hui Wang ◽  
Hong Sheng Lv

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.


2013 ◽  
Vol 772 ◽  
pp. 844-848
Author(s):  
Lin Zhang ◽  
Jian Chao Liu ◽  
Xing Yun Wang ◽  
Jian Feng Bai

Through the paleontology, lithology combination data,For Weihe basin Gushi hollow Tertiary the Zhangjiapo group unified hierarchical total divided into seven sections. According to coring, logging data to study the rock types and sedimentary structure,Summed up the logging of various sedimentary microfacies facies, clear in the study area is a shallow lake - a deeper lake - deep lake - deeper lake - shallow lake cyclic sedimentation.For single well facies analysis of typical wells in the region, the establishment of even well profile, determine the small layer of sedimentary facies the planar distribution concluded sedimentary facies model.


Author(s):  
Han Li ◽  
Xu Chang ◽  
Jinlai Hao ◽  
Yibo Wang

ABSTRACT Through downhole monitoring, the focal mechanisms of microearthquakes can be quantitatively determined, thus providing valuable information for characterizing the fracturing process and the in situ stress status. The double-couple (DC) and moment tensor (MT) source models are commonly used to study microearthquakes. However, the DC model fails to include non-DC mechanisms, and MT inversion from single-well data is still challenging. One possible way to address this is using the shear–tensile general dislocation (GD) source model. We provide a detailed comparison of the DC, GD, and MT models, and introduce the differences in their modeling and inversion theories. These three models are described by four, five, and six parameters, and correspond to a single point, a straight line, and the entire space in the Hudson source-type plots, respectively. Both the DC and GD models yield nonlinear inversions, whereas the MT inversion is linear. Synthetic tests set up from a field single-well monitoring case are performed to study the resolvability of the DC, GD, and MT models in single-well focal mechanism inversions. The results indicate that the inversion error increases from DC→GD→MT for a single-well acquisition system, and the GD and DC inversions are both stable, whereas the MT inversion deviates from the inputs in cases with a perfectly vertical receiver array, 5% model velocity perturbations, 10 m horizontal source location errors, or 40% noise levels. We also find that the focal mechanism inversion mainly depends on the horizontal source–receiver azimuth coverage, and that the nonvertical well direction is helpful for constraining single-well inversions. According to our study, focal mechanism inversions based on the GD model can obtain reliable solutions from near-vertical single-well data, which will help improve non-DC earthquake studies.


2013 ◽  
Vol 734-737 ◽  
pp. 418-421
Author(s):  
Yu Shuang Hu ◽  
Jiao Zhang ◽  
Shu Fen Liu ◽  
Xi Chen

Time-space-source dynamic controlling sand theory emphasized the size, supply and distribution of the source changes with time and space. Based on this theory, ramp-type, half-graben type and slots, grooves parallel-type sand control modes were established at Surennuoer oil field. According to the attribute maps and the sandstone thickness maps, the sand scope of nantun group can be determined, after identified the sand control point by using the fault throw statistic and 3D visualization technology. Sedimentary facies and the single well integrated histogram were used to verify the accuracy of the sand body divided. The results showed that: the sand control scope divide very accurately,and the sand control scope dovetail nicely with turbidite fan, braided channel and other sand-rich sedimentary facies.


2012 ◽  
Vol 546-547 ◽  
pp. 656-660
Author(s):  
Wan Jin Liu ◽  
Jin Chao An ◽  
Hui Zhou ◽  
Chao Su

The seismic attribute has multi-solution, and can not correspond to geological bodies exactly, a variety of seismic attributes information interpreted by changes in their characteristic parameters was prone to conflicts, the fusion technology of multi-attribute fuses the independent single-attribute in seismic data together, it can use the advantage of each attribute to display the characterization of geological body vividly. In this paper, we extract the attributes slice under the control of isochronous stratigraphic framework along layers, optimize the attribute using reference well data to select three independent attributes that can reflect lithological and physical properties, and fuse the three favorable attributes using the image of RGB fusion technology for better identification of sedimentary facies.


2014 ◽  
Vol 962-965 ◽  
pp. 160-163
Author(s):  
Si Si Cai ◽  
Wen Hui Huang ◽  
Meng Gong ◽  
De Yu Yan

This document studies the deposition condition in northeast Jizhong depression by using relevant data of cores, logging and scanning electron microscope. The result indicates that the study area has 7 kinds of lithofacies, including conglomerate, sandstone, siltstone, mudstone, bauxite, carbonate rock and coal seam . Bottom-up development in the study area cover tidal flat, lagoon, delta, meandering river and braided river, a total of five kinds of sedimentary facies. Benxi Formation, Taiyuan Formation and Shanxi Formation deposited in transitional facies, which has high generation potential of Hydrocarbon. Lower and upper Shihezi Formation is mainly a set of river deposition as a good reservoir. The top of upper Shihezi Formation and Shiqianfen Formation are mainly mudstone, which is conducive to seal oil and gas.


Author(s):  
Anita Mandal ◽  
Debasish Saha ◽  
Asit Kumar

AbstractBikaner–Nagaur basin is located in the northwestern part of India and lies on the rising flank of Punjab platform of Middle Indus basin in Pakistan. Existence of Neoproterozoic-Cambrian petroleum system was confirmed by the exploration activities in the western periphery of the basin, whereas vast areas of central and eastern parts remain unexplored. Knowledge of petroleum system in this unexplored part of the basin is limited due to non-availability of data. Recently, 2525 line km of regional 2D seismic data acquired for the first time by Government of India under National Seismic Program (NSP) unlocks the opportunity for comprehensive understanding of subsurface geology in unexplored part of the basin. Present work aims to interpret recently acquired 2D seismic data and integrate with available surface (outcrop) data, gravity and well data (drilled in western part of basin) for unfolding the petroleum system elements, structural configurations and stratigraphic features in the hitherto central-eastern part of the basin. Two Neoproterozoic-Cambrian hydrocarbon plays: (1) Jodhpur and (2) overlying Bilara/Hanseran Evaporite Group (HEG) were envisaged. Both the plays depicted distinctive seismic characteristics, structural alignment and distribution of reservoir, source and seal. Fluvio-deltaic sandstone within Jodhpur group and shallow marine fractured dolomites within Bilara/HEG showed potential reservoir characteristics whereas organic rich laminated dolomites, stromatolites and argillaceous litho-units within Bilara/HEG group have been predicted as prospective source. The Halite layers within HEG group were considered as effective regional seals. Fault bounded anticlinal structures associated with Cambrian compression have been identified as the main entrapment for hydrocarbon accumulation. The basin witnessed long tectonostratigraphic history with two major compressional phases Structures formed by Cambrian compression are likely to be charged as the time of source maturity and peak expulsion was later, during early Mesozoic period. Overall, the study indicates new opportunities and potential accumulation of hydrocarbon in the unexplored part of the basin.


2021 ◽  
Vol 290 ◽  
pp. 02012
Author(s):  
Yingzhi Liu ◽  
Yanyan Liu ◽  
Ying Chen ◽  
Shasha Yang ◽  
Bowang Wang

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.


1996 ◽  
Vol 36 (1) ◽  
pp. 209 ◽  
Author(s):  
D. B. Whittam ◽  
M. S. Norvick ◽  
C. L. Mclntyre

Increased exploration activity in Area A of the Timor Gap Zone of Cooperation between Australia and Indonesia (ZOCA) has created the need for revision of the existing stratigraphic framework of the region. A chronostratigraphic approach to the analysis of the Mesozoic and Cainozoic succession of Western ZOCA provides a framework for improved stratigraphic prediction. The framework is based on the identification of depositional sequences by the integration of seismic and well data. Genetically related depositional sequences have been grouped into seven 'megasequences' which reflect distinct stages in the tectonic development of the basin.The Mesozoic and Cainozoic succession in the Northern Bonaparte Basin was deposited in a marginal sag basin that was affected by Triassic to Lower Cretaceous extension related to continental separation along the northwest margin of Australia. Four stages are seen in the evolution of the basin since the end of the Permian. Relative tectonic quiescence during the Triassic preceded two cycles of extension related to continental separation during the Jurassic to Earliest Cretaceous. Continental separation was followed by the development of a Cretaceous/Tertiary passive margin and a subsequent phase of tectonism related to the Miocene/Pliocene collision of the Indo-Australian and Eurasian plates. A tentative correlation has been made between the megasequence framework of Western ZOCA and the geological succession exposed on Timor Island.The framework forms the basis for a system of common stratigraphic nomenclature for the Timor Gap. The model also assists in understanding the tectono-strati-graphic evolution of the basin and is a foundation for the development of new play concepts that will support continuing exploration activity in the area.


Minerals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 68
Author(s):  
Shiqi Liu ◽  
Yuyang Liu

As the northwestern area of the Junggar Basin is a key area for oil and gas exploration, the sedimentary facies of the Jurassic formations in the Wuerhe area has long been a focus of research. The target strata are Jurassic strata, including five formations: the Lower Jurassic Badaowan and Sangonghe, the Middle Jurassic Xishanyao and Toutunhe and the Upper Jurassic Qigu. Disputes over the are sedimentary facies division exist in this area. Considering the W105 well region in this area as an example, the overall sedimentary facies of single-well logging facies is analyzed and then expanded to two cross-sections and characterized. Based on previous studies, a detailed overview of the regional stratigraphy is obtained by well logs and other data. Then, two cross-sections are selected and analyzed. The single-well and continuous-well facies of 10 wells in the sections are analyzed to grasp the sand bodies’ spatial distribution. Finally, a planar contour map of the net to gross ratio is mapped to analyze the sources and the distribution of the sand bodies in each period. The sedimentary facies map is also mapped to predict the sedimentary evolution. The results show that the sedimentary facies of the Badaowan Formation in the study area was an underwater distributary channel of the fan-delta front, and the sand body spread continuously from northwest to southeast. The Sangonghe Formation entered a lake transgression period with a rising water level, at which time shore–shallow lacustrine deposits were widespread throughout the region. The period of the Xishanyao Formation entered a regression period, the northwest region was tectonically uplifted, and the central and southeastern regions facies were dominated by the fan-delta front and shallow lacustrine. During the Toutunhe Formation period, the northwest region continued to uplift and was dominated by delta plain facies. During the period of the Qigu Formation, the thickness of stratigraphic erosion reached its maximum, and the non-erosion area of the study area was mainly deposited by the fan-delta plain. Overall, the Jurassic system in the W105 well area is a fan delta–lacustrine–fan delta sedimentary system.


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