Integrated Modelling and Reservoir Characterization of Ataga Field, Niger Delta Basin, Nigeria

Integrated modelling, well correlation and petrophysical analysis were performed to characterize the reservoirs for optimum hydrocarbon correlation using 3-D seismic reflection data and suites of well logs from Ataga 5, 7, 10 and 11 wells respectively in Ataga field, shallow offshore, Niger Delta Basin, Nigeria. The study revealed the presence of two viable hydrocarbon bearing reservoirs, AT1 and AT2 and the average values of porosity, permeability, water saturation, hydrocarbon saturation, Net to Gross (NTG) and volume of shale are in the ranges of 15% - 77%, 44.5% - 75.5%, 25.5% - 85%, 15% - 75.5%, 0.70 - 0.88 and 0.11 - 0.38 respectively which goes further to show that the both reservoirs have fair characteristics that are suggestive of the presence of hydrocarbon accumulation. It can therefore be deduced that the permeability values are reflective of fair interconnectivity of pore spaces of sands within the well areas and their ability to transmit fluids, the depth and depth structural map generated for the horizons and structures shows that the most dominant trapping mechanism in the area under study is the crescentic growth fault and the rollover anticlines trending in the Northwest-Southeast direction and from the volumetric analysis. It can be deduced that the recoverable gas for AT1 and AT2 reservoirs is 2 × 106 mscf and 6 × 106 mscf respectively.

Structural Origin of Sinjar Anticline, NW Iraq

The Sinjar anticline is a double plunging, trending almost E-W in the northwestern part of Iraq. It extends in Syria for about 42 km, whereas in Iraq, its length is about 91 km, and the width is about 31 km. The northern limb (45° - 80°) is steeper than the southern limb (15° - 25°), with average plunges dip of 35° and axial plane dipping of 47.5° southwards. The exposed rocks in the anticline range in age from Upper Cretaceous, represented by the Shiranish Formation, to Upper Miocene, represented by the Injana Formation. Google Earth image was used to calculate structural data, which were used to indicate the structural origin of the Sinjar anticline. This was achieved by calculating the Aspect Ratio (AR), Fold Symmetry Index (IFS or IFS), and length of the mountain front (FS). Accordingly, it was found that the structural origin of the Sinjar anticline is a fault-bend fold.

Lithostratigraphy, Structure, Geological History, Economic Geology and Paleontology of Mari Bugti Hills and Surrounding Areas of Balochistan, South Punjab and North Sindh (Pakistan)

Mari Bugti hills and surroundings belong to Sulaiman basin (fragment of Gondwana) lies under the territory of Balochistan, South Punjab and North Sindh (Pakistan) but luckily have diverse marine and terrestrial sediments varying in age from Triassic to Recent, petroleum and a large number of mineral resources especially huge gypsum and cement resources, numerous suitable anticlinal structures and world-famous paleontology. The large-sized poripuchian titanosaurs, theropods, mesoeucrocodiles, pterosaur, bird and snake were reported from the latest Cretaceous Vitakri Formation, and largest terrestrial mammals and eucrocodiles were reported from the Oligocene Chitarwata Formation and other mammals were also reported from Late Paleogene and Neogene terrestrial deposits. Previously part of this area was not mapped due to remoteness and security problems but recently the mapping of these areas was started. Further, the structural and geological maps of previously omitted parts are added here. After performing the multidisciplinary field investigations by senior author, the corresponding results were obtained. The main objective of this work is to focus on the lithostratigraphic deposits, structure, geological history, economic geology and paleontology of the Mari Bugti Hills and surrounding areas.

Stratigraphy and Structure of Dhamtaur Area, District Abbottabad, Eastern Hazara, Pakistan

Pre-Cambrian to Paleocene age sedimentary rocks predominantly characterize the fold and thrust belt of eastern Hazara division. The Hazara Slate Formation is the oldest rock unit which represents the Precambrian sequence. The Permian and Triassic sequences are missing. The Jurassic sequence comprises Samana Suk Formation whereas the Cretaceous exposed is Chichali and Lumshiwal formations. The Eocene sequence consists of Nammal and Sakessar formations. The structural fabric of the area is mainly attributed to a series of northwest trending parallel to en echelon anticlines and synclines. Most of these folds are found to be asymmetric and are Northwest facing. Several thrust faults verging both to the north have been mapped that generally dissect the forelimbs of the anticlinal structures. But the following study going to be focus on surface structural features as well as subsurface projections of folds and faults. Study of such structural features has get prime importance in economic geology such as petroleum geology, mining geology and engineering geology. In our study area subsurface projection of folds and faults along the structural transects of the area suggests that these structures have formed as a result of shortening associated with ramping from a regional basal decollement. All the structures clearly demonstrate that the eastern Hazara area has been subjected to compressional deformation/stresses oriented northeast southwest. The repetition of rock units indicates, folding in the area and thrusting of Pre-Cambrian Hazara Formation over younger Paleocene Lockhart Formation, evidence of thrust fault. There are unconformable contacts between Hazara and Samana Suk, Chichali and Lumshiwal, Kawagarh and Hangu and Lockhart formations indicate fluctuation in the environment of deposition. The Bagnotar Fault, Dhamtaur syncline and Thai anticline are the major structural features identified and reported in the study area.

Evaluation of Hydrocarbon Reserve in AD Field, Offshore Niger Delta

This study was carried out to quantify uncertainty in the reserve estimate of hydrocarbon in the reservoirs of AD Field, offshore, Niger Delta. Three Dimensional (3D) seismic data and log suites of seven wells (AD1 to AD7), gamma ray, resistivity, neutron and bulk density logs, well deviation and checkshot data in AD Field acquired from companies in the area. Twelve faults (Fault1 to Fault12) were identified from seismic structural interpretation while Six hydrocarbon-bearing sand intervals (Sand A - F) were delineated from the petrophysical analysis. The sand intervals thin-out basin wards, suggesting a prograding sequence. The porosity of the sand intervals ranges between 0.19 and 0.32, implying good to excellent porosity. The water saturation values ranged from 0.19 to 0.39, indicates a prospective accumulation of hydrocarbon. Sand A reservoir had the largest accumulation of hydrocarbon in-place with hydrocarbon pore volume of 2343 106 Reserve Barrel (RB), Stock Tank Oil-Initially-In-Place (STOIIP) of 175 MMbbl and gas initially-in-place of 0.30 TCF. The coefficient of variation in the reserve estimates of the reservoirs ranged from 0.09 to 0.15 indicating very low uncertainty of substantial hydrocarbon reserve that could be exploited.

The Seismogenic Structure of the 2010 Suining Ms 5.0 Earthquake and its Geometry,Kinematics and Dynamics Analysis

In January 2010, the Suining Ms5.0 earthquake occurred in central Sichuan Basin, with the epicenter in Moxi-Longnvsi structural belt and a focal depth of 10 km. Based on structural interpretations of seismic profiles in this area, we recognized a regional detachment fault located at a depth of 9-10 km in the Presinian basement of the Suining area, transferring its slipping from NW to SE orientation. This detachment fault slipped from NW to SE, and underwent several shears and bends, which caused the basement to be rolled in and the overlaying strata fold deformation. It formed a fault-bend fold in the Moxi area with an approximate slip of 4 km. Correspondingly, the formation of the Moxi anticline is related to the detachment fault. With the earthquake＇s epicenter on the ramp of the detachment fault, there is a new point of view that the Suining earthquake was caused by re-activation of this basement detachment fault. Since the Late Jurassic period, under the influence of regional tectonic stress, the detachment fault transfered its slip from the Longmen Mountains （LMS） thrust belt to the hinterland of the Sichuan Basin, and finally to the piedmont zone of southwest Huayingshan （HYS）, which indicates that HYS might be the final front area of the LMS thrust belt.

The Unique Folding Style in the Zagros Simply Folded Belt, the Kuh-e Qazi Anticline, South Iran

The study area is located in the Zagros Simply Folded Belt of Iran and in the interior Fars sub-basin (175 km from Persian Gulf). The Zagros fold-thrust belt is home to one of the largest petroleum producing reservoirs in the world. Structures in this area have complications and the study anticline has unique structures in the Fars region. In the study area, the Kuh-e Qazi anticline due to special fold style and rotation toward Northeast is the unique structure between anticlines of the Zagros belt. This anticline is fault bend fold and plunge of the anticline in eastern part rotated toward Northeast along with the Nezamabad fault trend. In this area, the Kuh-e Qazi anticline has asymmetric structures and some faults such as the Nezamabad and the Sarvestan strike slip fault effect on this anticline. The geometry of anticlines in the Zagros fold-thrust belt is affected by the type of deformation and mechanical behavior of stratigraphic units specially detachment units. The purpose of this research is to determine of folding pattern of the Kuh-e Qazi anticline and define structural features affected on them in the study area. This paper presents a part of the results of a regional study of the Fars province in the Zagros Simply Folded Belt, based on original fieldwork, satellite images, structural sections, geological maps and well data. Also, we use some software as Global Mapper and Tectonics FP for preparing some data.?Based on the research, which have been done, the boundary between ductile and frictional substrates causes rotation as a result of lateral, along-strike migration of the ductile substrate. The ductile or viscose layer in the study area is Hormuz Series. Due to lack or thinning of Hormuz salt over the Gavbandi basement high and in the eastern side of the Nezamabad basement fault, causes translation of strain and anticlockwise rotation in Southeast of the Kuh-e Qazi anticline toward Northwest unlike foreland basin due to the Nezamabad fault activity. This style between all of the anticlines in the study area is unique that rotates unlike foreland basin. In addition, influence on anticlockwise rotation, extensional stress has been created and then salt dome cropping out in Southeast of the Kuh-Qazi anticline. One of the best evidence for effect of extensional stress is triangular facets in this part of the study anticline. Based on folding analysis (geometry of axial plane and fold orientation), it is clearly confirmed that the translation of strain and anticlockwise rotation in Southeast of the Kuh-e Qazi anticline toward Northwest has been formed by basement fault activity as the Nezamabad fault in the boundary between ductile and frictional substrates of the study area.

Breakthrough of shallow shale gas exploration in Taiyang anticline area and its significance for resource development in Zhaotong, Yunnan Province, China

Based on exploration and development results and evaluation of marine shale gas in South China in the past ten years, in view of the features of "high maturity, strong tectonic reformation and high shear stress" of the shale in Zhaotong exploration zone in the Yunnan and Guizhou Plateau, as well as the key issues of long time diffusion and leakage of shallow shale gas, and the preservation conditions, the factors controlling shallow shale gas sweet spot and key zone selection evaluation technology of shale gas are investigated. From 2017 to 2018, the first significant exploration breakthrough was made in the Taiyang anticline at a buried depth of 700 to 2 000 m, discovering large-scale proved geological reserves of shallow shale gas. By examining the accumulation conditions and sweet spot control factors of the shallow shale gas in this area, it is found that the accumulation and productivity potential of shale gas in the mountainous area with complex structure outside basin are controlled by five factors:(1) The gas-rich area has weak tectonic reformation and good preservation conditions on the whole, taking on typical anticline trap occurrence mode.(2) The gas-rich area is in over-pressure state and high in shale gas content.(3) The gas-rich area has high quality shale and thus superior source rock condition.(4) The gas-rich area has high quality reservoirs dominated by class I.(5) The shale gas reservoir in the gas-rich area has high content of brittle minerals and small difference between maximum and minimum horizontal stresses which are conducive to hydraulic fracturing. The innovative practice and core technologies formed during the exploration and production capacity construction of shallow shale gas in the Zhaotong demonstration zone have great reference significance for shallow shale gas exploration and development in other areas.

Folding Style of the Kuh-e Siah Anticline in the Sarvestan Area, Interior Fars, Zagros, Iran

The Kuh-e Siah anticline is located in the Sarvestan area of the Fars province (186 km to Persian Gulf) and Interior Fars sub basin. This anticline is a fault bend fold and is located in the Sarvestan fault zone with Northwest-Southeast trend. The Sarvestan fault zone has caused main deformation by dextral strike slip activity in southern part of the Zagros fold-thrust belt. The main aim of this paper is to determine of fold style elements and folding pattern of the Kuh-e Siah anticline. This paper presents part of the results of a regional study of the Fars province in the Zagros Simply folded belt, based on original fieldwork, satellite images, structural sections, geological maps and well data. In addition, we used some software as Global Mapper and Tectonics FP for prepared some data. Folds, which are close sideways, are neutral and these require special attention. It is remarkable that, in all sections of the Kuh-e Siah anticline, fold type is close and in the middle part of the anticline, fold type is different with other parts. In the middle part, fold type is upright-moderately gently plunging. On the other hand, in northwestern and southeastern parts fold type is similar together. These results maybe show that fold style follow that fold sigmoidal shape that created with two-fault segment of the Sarvestan fault zone in the study area. Therefore, it seems that the Kuh-e Siah anticline has suffered high deformation in the Sarvestan fault zone and this fault zone has created shear zone.

The Elements of Fold Style Analysis in the Khaftar Anticline, Zagros, Iran

The Study area is located in the Zagros Simply Folded Belt of Iran and in the interior Fars sub-basin. The Khaftar anticline is located in the West, North-West of Jahrom city in the Fars province (148 km distance from Persian Gulf). The trend of Khaftar anticline has three orientations, consist of North-Northeast, East-West and South-Southwest. This anticline has asymmetric structure and some faults with large strike separation observed in this anticline. In the study area, stratigraphic units are affected by many faults in this area. Also one salt plug cropping out in the middle part of the Khaftar anticline. Maybe this salt plug affected on the stratigraphic units and geometry of structure. Description of fold geometry is important because it allows comparisons within and between folds and allow us to recognize patterns in the occurrence and distribution of fold systems. The main aim of this paper is determination of fold style elements and folding pattern of the Khaftar anticline. This paper presents a part of the results of a regional study of the Fars province in the Zagros Simply folded belt, based on satellite images, geological maps, and well data. Some data, such as geological maps and geological regional data were prepared and provided by the National Iranian Oil Company (NIOC). Because of the Khaftar anticline, has complex structure, the analysis of fold style elements is seems necessary. Therefore, in further studies on this structure the changes of fold style elements will be analyzed and investigated from east to west in the different parts of this anticline. The activity of Nezamabad sinistral strike slip fault in the Khaftar anticline causes changes of axial plane characteristics and fold axis. Some of the results such as folding style analysis, how position of salt plug, changes of fold type and main structural changes (rotation of fold axis and 2.5 km displacement in this anticline) show main changes in the middle parts of the Khaftar anticline. It seems that, these changes have formed by activity of the Nezamabad fault and this fault’s activity same as fault zone.

Structural Style in the Khalfani Anticline, Coastal Fars, Zagros Fold-Thrust Belt

The Khalfani anticline is located in the Coastal Fars (Zagros, adjacent Persian Gulf). This anticline with Northwest-Southeast trend is a fault bend fold. In the study area, the Khalfani anticline has increased elevation from West to East with three distinct humps. The major faults in the study area are the Hendurabi and the Razak sinistral strike slip faults. Because analysis of fold and their folding styles in different parts system is important, the analysis of folding style elements is necessary for structural studies. The main aim of this research is structural style analysis based on fold style elements in the Khalfani anticline. This analysis is important for progress in hydrocarbons exploration in the Coastal Fars area. In this research, we used Tectonics FP and Global Mapper Software for preparing some data in our study. In addition, we used the common classification of folds for our research. Based on given results, the folding pattern of this anticline has indicated that the fold style is same in different parts of the Khalfani anticline. In the study area, based on classifications of fold in different methods, fold style is same together. Fold, with close sideways requires special attention as structural view;then the Khalfani Anticline with close style in all parts has special deformation and folding style. It seems that in the study area, folding style and variation of structural style have been created by effect of the Razak and the Hendurabi sinistral strike slip fault. Because these faults are basement or deep-seated faults, special folding style and special deformation can be formed in the study area. In addition, the Khalfani anticline in the study area has restricted within the Razak and the Hendurabi sinistral strike slip faults.

Tectonic and geological setting of the earthquake hazards in the Changning shale gas development zone, Sichuan Basin, SW China

Hydraulic fracturing is a key technology in shale gas extraction,whether hydraulic fracturing induces earthquakes has become a hot topic in the public and the focus of scholars’research.The urgency of shale gas mining and the catastrophic nature of earthquakes highlight the urgent need to study this issue.The Changning anticline at the southern margin of the Sichuan Basin is a key area for shale gas exploitation.Taking this as an example,this paper applies the velocity model of the study area to reposition the M5.7 magnitude earthquake on December 16,2018 and the M5.3 magnitude earthquake on January 03,2019 and their aftershock sequence in this area.Using shale gas exploration drilling and reflection seismic data to carry out structural analysis,and recovering the tectonic geological setting of earthquake occurrence by restoring the formation process of the Changning anticline,to further explore the seismic mechanism.Our results show that the Changning anticline is a large basement fault-bend fold,and the displacement of the fault forming the anticline is 18 km,and the Changning anticline absorbs 33%of the fault slip.The Silurian Longmaxi Formation of the Changning anticline experienced larger-parallel shearing along underlying basement faults,forming a micro-fracture system.The footwall ramp of the basement fault is reactivated at present,earthquakes in this area mostly occur along the footwall ramp of the basement fault and above and below it.The anticlinal and synclinal hinge zones are also the earthquake concentration areas,but the earthquake magnitude decreases upwards along the kink-band,and small earthquakes below M2.0 occur in the Silurian Longmaxi Formation.So far,the earthquake in the Changning anticline mainly occurred in the southern limb of the anticline,which is a natural earthquake formed along the footwall ramp of the basement fault.The earthquakes in the Changning area are possible related to the geo-tectonic setting for the southeast outward compression of the Qinghai-Tibet Plateau at present,the moderate or large-scale earthquakes in the southwest Sichuan Basin are mainly due to the reactivation during late Quaternary of the earlier formed faults.It is suggested to carry out scientific monitoring of seismic activities in shale gas development zones.

The Discovery of Deep Potassium and Lithium Resources in the Huangjinkou Anticline, Northeast of Sichuan

Objectives Important clues have been found for potassium prospecting in the Huangjinkou anticline of the northeast Sichuan Basin in the 1970s(Zheng et al.,2015;Lin et al.,2004).In 2008,China Geological Survey launched a prospective investigation of potash resources in the western region of China,and the local governments and private-owned enterprises also responded positively.Then,

Structural Style in the Zagros Fold-Thrust Belt: The Gavbast Anticline, Coastal Fars

The Gavbast anticline is located in the Coastal Fars area of the Zagros folded belt, with north-south trend. The study anticline is restricted to the Bavush and Paskhand anticlines from North, the Gezzeh and Dehnow anticlines from South, the Varavi anticline from West and Nakh anticline from East (Figure 1). Description of fold geometry is important because they allow comparisons within and between folds and pattern-recognition in addition to occurrence and distribution of fold systems. The main goal of this paper is to define folding style of the Gavbast anticline and define structural features affected on them in the study area. In this research, we used the Tectonics FP software, Global Mapper software and geological maps and reports of Iranian National Oil Company. In addition, we used common classification of fold for indicating of folding mechanism of the Tabnak anticlinal structure. In the Gavbast anticline, fold style elements in all parts of this anticline have been calculated and analyzed for indicating of folding style mechanism. The results of this method have been shown the folding geometry changes accurately. The Gavbast anticline is gentle in structural sections D-D' and G-G' to K-K'. The anticline is an open fold in the L-L' section. Also fold type in the E-E' and F-F' sections of the Gavbast anticline is steeply inclined sub-horizontal. These sections are located between the Razak (western part) and Hendurabi fault (eastern part). It seems that E-E' and F-F' parts in the Gavbast anticline have been suffered most deformation affected by the Razak and Hendurabi faults. At the end of, it seems that, the Razak and Hendurabi faults have major effects on folding style. This structure is a very good sample for effect of strike slip faults on the folding geometry and for this reason;the Gavbast anticline is considered a special structural style in the Zagros fold-thrust Belt.

Folding Mechanism in the Asmari Anticline, Zagros, Iran

Asmari anticline is a NW-SE fold in the Dezful Embayment sub-basin of Zagros. Fars group (Late Moicene-Quaternary) is cropping out in the cores of anticlines in this area, but Pabdeh and Asmari formations (Oligocene-Early Miocene) have cropped out only in Asmari anticline in the Dezful Embayment. Therefore, it has formed a unique exposure for above formations. In order to this situation, folding mechanism of Asmari anticline has investigated in this research. According to our?results, Asmari anticline has two mechanisms: flexural-slip in post-Cretaceous sequences?(Khami-Quaternary) and fault-bend folding in pre-Cretaceous sequences. So, there is a hybrid folding mechanism that has introduced for the first time in this paper.

Folding Style Analysis of the Tabnak Sweet Gas Field, Zagros, Iran

The Zagros fold-thrust belt in Iran is home to one of the enormous petroleum producing reservoirs in the word. The Tabnak gas field in this belt is one of the enormous sweet gas fields that discovered on the land. This anticlinal structure is located in the Coastal Fars sub-basin and is bounded from North by the Varavi gas field, from South by the Kuh-e Madar anticline, from East by Assaluyeh gas field and from West by Kuh-e Dehnow anticline. Its length is about 80 km and width is about 15 km. This structure is asymmetric anticline and is located with irregular near the Assaluyeh gas field. The Tabnak gas field is deepest structure between anticlines in the Coastal Fars area. This gas field has a special place for accommodating the enormous Hydrocarbon resources and for this reason, it is very important for Iran country. In this structure, the Dashtak, Kangan and upper Dalan Formations have Hydrocarbon. Analysis and description of fold style elements are essential for structural studies. Based on this case, the comparison of the fold styles and folding mechanism is possible. The main aim in this research is the analysis of the fold style elements of the Tabnak anticline for determining the folding pattern and tectonic regime on this structure. This case has very important for Hydrocarbon exploration between gas fields in the Fars area. In this research, we used the Tectonics FP software, Global Mapper software and geological maps and reports of Iranian National Oil Company. In addition, we used common classification of fold for indicating folding mechanism of the Tabnak anticlinal structure. Based on analysis of the fold style elements, the Tabnak anticlinal structure has variation in fold style. This structure has three different fold styles in different parts. The changes of fold axis, axial plane characteristics and fold classification confirmed several fold styles in different parts of the Tabnak anticline. These changes are observed specially in B-B', F-F' and G-G' sections of this anticline. It seems that these parts have been suffered more deformation in the study anticline. In addition, based on interlimb and folding angle, fold type is close type in all of parts. The close type required more accuracy, because the close type may be ensigns of complication regime. In the study area, G-G' and F-F' section of the Tabnak gas field probable show folding style changes have been affected by Gavbandy Paleo-high.

Reservoir controlling differences between consequent faults and antithetic faults in slope area outside of source: A case study of the south-central Wenan slope of Jizhong Depression, Bohai Bay Basin, East China

The control effects of different occurrence faults on oil and gas accumulation and distribution in the outer slope area of oil and gas reservoirs were studied taking the south-central Wen’an slope of the Jizhong depression in the Bohai Bay Basin as an example.Based on 3D seismic data and the distribution of oil and water,the controlling differences between consequent fault and antithetic fault were analyzed and compared from the formation and evolution rule of faults and the formation mechanism of fault traps,including development positions of the consequent fault traps and antithetic fault traps,oil and gas distribution horizon adjusted by fault and formation period of fault traps.The differences between consequent faults and antithetic faults in controlling reservoirs have three main aspects:(1)Consequent fault traps and antithetic fault traps are in different positions,the consequent fault traps are at the segmented growing point in the hanging wall of"hard-linkage"faults,while the antithetic fault traps are developed in the position with the largest throw in the footwall because of tilting action;(2)The two kinds of faults result in different oil and gas distribution vertically,oil and gas adjusted by consequent faults is distributed in a single layer or multi-layers,while oil and gas adjusted by antithetic faults occur in single layers;(3)The two kinds of fault traps are formed in different periods,the consequent fault traps are formed at the time when the related faults enter the stage of"hard-linkage",while the antithetic fault traps are formed at the beginning of the fault active period.

Hydrocarbon Trap and Folding Style of the Pishvar Anticline, Sub-Coastal Fars, Zagros

The Pishvar anticline with Northwest-Southeast trend is located in the Sub-Coastal Fars area. This anticline with 80 Km length and 5 - 7 Km width is located in western part of the Lar area. The Pishvar anticline has two closures that are separated together by smooth down-warp. The oldest units that have outcropped on the surfaces are Asmari and Jahrom Formations. The most faults that observed on the Pishvar anticline are Normal fault. In the study area, the Razak and Hendurabi faults are main faults. These faults are strike slip with sinistral displacement. This anticline has greater dip in Northern flank compared to Southern flank. In this research, the main aim is folding style analysis, based on Description of fold geometry for indicate hydrocarbon trap structure in the Pishvar anticline. Description of fold geometry is important because they allow comparisons within and between folds and pattern-recognition in addition to occurrence and distribution of fold systems. We used Tectonics FP and Global Mapper Software for prepared some data in our study. In addition, we used the common classification of folds for our research. Based on results, the folding pattern of this anticline has indicated the fold style has different type in different parts of the Pishvar anticline. According to fold style variation and deformation analysis from B-B’ to C-C’ parts of the study anticline, it seems that the location of the Razak sinistral strike slip fault has existed in this parts. Fold style change can show this case. In addition, fold style variation and deformation analysis from E-E’ to F-F’ parts of this anticline has been affected of the secondary fault that is related to the Razak sinistral strike slip fault. We introduced this fault for first time. Finally, Based on results in this research, in western part there is little probability for access to hydrocarbon trap in upper horizons, unless the exploratory drilling continues to the deeper horizons.

Application of 3D Acquisition Design Technology in HCX Gas Storage Project*

In view of the shallow buried depth of the target layer and it is difficult to obtain high-quality seismic data of HCX gas storage project, based on the acquisition parameters of the adjacent area, the 3D acquisition technical scheme is designed for focusing on the imaging of the top of HCX high-steep anticline. By optimizing the acquisition parameters and the excitation and receiving conditions, the acquisition of high-resolution and high signal-to-noise ratio seismic data is guaranteed to meet the demand of fracture prediction and reservoir prediction.

Numerical simulation of hydraulic fracture propagation in laminated shale reservoirs

The main area of the Jiaoshiba anticline of the Fuling shale gas field was taken as the research object,laboratory rock mechanical experiments and direct shear experiments were conducted to clarify the mechanical anisotropy characteristics and parameters of rock samples with rich beddings.Based on the experimental results,a 3D fracture propagation model of the target reservoir taking mechanical anisotropy,weak bedding plane and vertical stress difference into account was established by the discrete element method to analyze distribution patterns of hydraulic fractures under different bedding densities,mechanical properties,and fracturing engineering parameters(including perforation clusters,injection rates and fracturing fluid viscosity).The research results show that considering the influence of the weak bedding plane and longitudinal stress difference,the interlayer stress difference 3–4 MPa in the study area can control the fracture height within the zone of stress barrier,and the fracture height is less than 40 m.If the influence of the weak bedding plane is not considered,the simulation result of fracture height is obviously higher.Although the opening of high-density bedding fractures increases the complexity of hydraulic fractures,it significantly limited the propagation of fracture height.By reducing the number of clusters,increasing the injection rate,and increasing the volume and proportion of high-viscosity fracturing fluid in the pad stage,the restriction on fracture height due to the bedding plane and vertical stress difference can be reduced,and the longitudinal propagation of fractures can be promoted.The fracture propagation model was used to simulate one stage of Well A in Fuling shale gas field,and the simulation results were consistent with the micro-seismic monitoring results.