Structural Study of Faihaa Oil Field in Basra South of Iraq

This study used structural contour maps to carry out the geometrical analysis for Faihaa structure in Basra southern Iraq. The study used row data of well logs and structural maps while Softwares were Didger 4, Stereonet v.11 and Petrel 2017 Faihaa Oil Field is located at an eastern part of the Mesopotamian Zone within the Zubair Subzone, characterized by subsurface geological structures covered by Quaternary sediments. These structures are oriented in the NW-SE direction in the eastern part of the band and the N-S direction in the southern region, and some in the direction NE-SW. The Faihaa Oil Field shows that is an Anticline structure. The average dip value of an axial surface is 89.7° while the plunge of hinge line between 4–4.2 in North-West direction referred to that Faihaa Structure is upright and gentle fold. Based on the Thickness ratio and axial angle, the Faihaa Structure is thickened Fold. The eastern limb of the fold is longer than the western limb, so Faihaa Oil Field is an asymmetrical structure. The difference in dimensions (5<Length / Width < 2) confirmed the brachy fold of the Faihaa structure.

Structural Reservoir Characterization of Akkas Gas Field, Western Iraq: Implications for Hydrocarbon Recovery

Akkas Field is a structural trap with a sandstone reservoir that contains proven gas condensate. The field is a faulted anticline that consists of the Ordovician Khabour Formation. The objective of this research is to use structural reservoir characterization for hydrocarbon recovery. The stratigraphic sequence of the Silurian and older strata was subjected to an uplift that developed a gentle NW-SE trending anticline. The uplifting and folding events developed micro-fractures represented by tension cracks. These microfractures, whether they are outer arc or release fractures, are parallel to the hinge line of the anticline and perpendicular to the bedding planes. The brittle sandstone layers of the reservoir are interbedded with ductile units of shale. The sandstone layers accommodate the formation of micro fractures that play a major role to increase the secondary porosity. The gas and condensate have been stored mainly through the micro fractures. Two types of drilling have been used for experimental gas production, vertical and horizontal. Horizontal drilling was parallel to both hinge line of the anticline and micro fracture surfaces that was conducted and doubled the gas production of the vertical well multiple times. However, if used the third type of drilling, directional, that is perpendicular to the hinge line and parallel to the beddings of both flanks of the anticline gas production will increase more than the horizontal drilling. The directional drilling will become perpendicular to the fracture surfaces and allow the gas and the condensate to flow into the well from all directions. Additionally, it will reduce the effect of both semi – liquid hydrocarbon condensate and vertical sediment barriers.

The Geology of Eketahuna (N.Z.M.S.1. N.153)

<p>An interesting rhythmic sequence consisting of massive mudstone and groups of graded beds each about 10 ft thick is exposed near Alfredton, in the southern part of the North Island. During Opoitian time, rotation along a north-east-trending hinge line west of Alfredton caused one side of a fault block to be relatively uplifted and the other depressed, at intervals of several tens of thousands of years, while sedimentation from south-west-flowing turbidity currents was in progress. The sandy fraction of post-faulting turbidity currents were channelled along the depressed side just to the east of the submarine fault scarp, while on the middle and upper slopes of the tilted block mud was deposited from the turbidity-current clouds. As sedimentation proceeded, graded beds on-lapped eastwards up the slope of the tilted block and across the area where muds had been deposited. Later tilting of the block initiated a new rhythm.</p>

The Geology of Eketahuna (N.Z.M.S.1. N.153)

<p>An interesting rhythmic sequence consisting of massive mudstone and groups of graded beds each about 10 ft thick is exposed near Alfredton, in the southern part of the North Island. During Opoitian time, rotation along a north-east-trending hinge line west of Alfredton caused one side of a fault block to be relatively uplifted and the other depressed, at intervals of several tens of thousands of years, while sedimentation from south-west-flowing turbidity currents was in progress. The sandy fraction of post-faulting turbidity currents were channelled along the depressed side just to the east of the submarine fault scarp, while on the middle and upper slopes of the tilted block mud was deposited from the turbidity-current clouds. As sedimentation proceeded, graded beds on-lapped eastwards up the slope of the tilted block and across the area where muds had been deposited. Later tilting of the block initiated a new rhythm.</p>

Geology of Bajalia Anticline of the Low Folded Zone of Iraq

Bajalia Anticline is located about 60km northeast of central Amarah city in Al-Teeb area near Iraq-Iran border. Field and laboratory works were conducted to study topography, geomorphology, stratigraphy, and structural geology of Bajalia Anticline. The Anticline has a longitudinal shape with about 29km in length and 5-7km in width. Injana, Mukdadiya, and Bai Hassan formations are the three formations that were recognized in the study area. The geometrical structural analysis depicts that the Anticline is non-cylindrical, asymmetrical, close, sub-horizontal, steeply inclined, and linear fold. Most of the fractures in the Anticline are joints. These joints were classified based on the tectonics axes, which are a, b, and c, into ac, bc, and hol. A major reverse fault is located at the margin of the southwestern limb parallel to the fold axis with about 25km length. This fault is responsible on the vergence of the Anticline and overturned part of the southwestern limb. The Anticline was formed as a result of the collision between the Arabian and Iranian plates during the Late Tertiary. The maximum stress axis, which is caused by collision, is perpendicular to the hinge line. The geometrical and genetic classification indicates that the Anticline was formed by the high folding intensity and with a role of evaporites layers.

Multimodality imaging anatomy of interatrial septum and mitral annulus

The detailed anatomy of the interatrial septum (IAS) and mitral annulus (MA) as observed on cardiac magnetic resonance, computed tomography and two-dimensional/three-dimensional transthoracic and transesophageal echocardiography is reviewed. The IAS comprises of two components: the septum primum that is membrane-like forming the floor of the fossa ovalis (FO) and the septum secundum that is a muscular rim that surrounds the FO. The latter is an enfolding of atrial wall forming an interatrial groove. Named Waterston’s groove, it is filled with adipose tissue on the epicardial side. Thus, the safest area for transseptal puncture (TSP) is within the limits of the FO floor, which provides direct interatrial access. While crossing an intact septum is a well-established procedure, TSP is a more complex and time-consuming procedure in the presence of patent foramen ovalis, aneurysmal FO or atrial septal defect closure devices. MA comprises two distinctive segments: an anterior-straight and a posterior-curved segment. The posterior MA is a thin, discontinuous fibrous ‘string’, interspersed with adipose tissue, where four components converge: the atrial and ventricular musculature, epicardial adipose tissue and the leaflet’s hinge line. In parts of where this fibrous string is deficient or absent, the posterior leaflet is inserted directly on ventricular and atrial myocardium rendering the MA less robust and producing an ‘asymmetric’ dilation. The marked vulnerability of posterior MA to calcifications might be due to its insertion on the crest of ventricular myocardium being subject to friction injury due to the contraction and relaxation of LV.

Implementation of dimensional management methodology and optimisation algorithms for pre-drilled hinge line interfaces of critical aero assemblies – A case study

A dimensional management procedure is developed and implemented in this work to deal with the identification of the optimum hole diameter that needs to be pre-drilled in order to successfully join two subassemblies in a common hinge line interface when most of the degrees of freedom of each subassembly have already been constrained. Therefore, an appropriate measure is suggested that considers the assembly process and permits the application of optimisation algorithms for the identification of the optimum hole diameter. The complexity of the mechanical subassemblies requires advanced 3D tolerance analysis techniques to be implemented and the matrix method was adopted. The methodology was demonstrated for an industrial, aerospace engineering problem, that is, the assembly of the joined wing configuration of the RACER compound rotorcraft of AIRBUS Helicopter and the necessary tooling needed to build the assembly. The results indicated that hinge line interfaces can be pre-opened at a sufficiently large size and thus, accelerate the assembly process whilst the suggested methodology can be used as a decision-making tool at the design stage of this type of mechanical assembly.

Lattice organs and newly characterized submarginal pore-plates and pore-fields of the carapace in Ascothoracida (Crustacea: Thecostraca)

Lattice organs on the dorsal part of the carapace were examined by scanning electron microscopy (SEM) in females, males, and/or cypridiform ascothoracid-larvae (in the ascothoracid-larva I stage, for the first time ever) of six species of Ascothoracida representing four genera and three families: Waginella sandersi (Newman, 1974), W. ?metacrinicola (Okada, 1926), and Gorgonolaureus muzikaeGrygier, 1981 (family Synagogidae); BaccalaureusBroch 1929, unidentified species (Lauridae); and Ascothorax gigasWagin, 1968 and A. synagogoides (Wagin, 1964) (Ascothoracidae). All were of the “keel in a trough” or “tube in a trough” type, but they varied even more than those of previously studied ascothoracidans in number, form, orientation, and terminal pore position. Such extensive variability, summarized graphically herein, limits the potential utility of Ascothoracida (parasites of anthozoans and echinoderms) as an out-group for polarizing lattice organ character-state variation in Cirripedia (free-living and parasitic barnacles). While the ground-pattern of lattice organs in Thecostraca (comprising Ascothoracida, Cirripedia, and Facetotecta, or “y-larvae”) includes two anterior and three posterior pairs, ascothoracid-larvae and males of AscothoraxDjakonov, 1914 and DendrogasterKnipovich, 1890 (family Dendrogastridae) have only two posterior pairs; evidence as to which pair is missing is discussed. The hypothesis that dorsal setae in thecostracan nauplii are the precursors of lattice organs in later developmental stages is reexamined; one-to-one positional matching of such setae to lattice organs is difficult in Ascothoracida. Newly characterized structures of unknown function, termed “reticulated pore-plates”, exist along the hinge line in a juvenile male of G. muzikae. The “pits” reported earlier along the anterior valve margin in ascothoracid-larva II of A. synagogoides are actually clusters of pores that may be homologous to these pore-plates. Potentially homologous pore-fields in other ascothoracidans are reviewed from the literature or described anew using SEM.

Co-location of the downdip end of seismic locking and the continental shelf break

&lt;p&gt;Along subduction margins, the morphology of the near shore domain records the combined action of erosion from ocean waves and permanent tectonic deformation from the convergence of plates. We observe that at subduction margins around the globe, the edge of continental shelves tends to be located above the downdip end of seismic coupling on the megathrust (locking depth). Coastlines lie farther landward at variable distances. This observation stems from a compilation of well-resolved coseismic and interseismic&lt;span&gt;&amp;#160; &lt;/span&gt;coupling datasets. The permanent interseismic uplift component of the total tectonic deformation can explain the localization of the shelf break. It contributes a short wave-length gradient in vertical deformation on top of the structural and isostatic deformation of the margin. This places a hinge line between seaward subsidence and landward uplift above the locking depth. Landward of the hinge line, rocks are uplifted in the domain of wave-base erosion and a shelf is maintained by the competition of rock uplift and wave erosion. Wave erosion then sets the coastline back from the tectonically meaningful shelf break. We combine a wave erosion model with an elastic deformation model to show how the locking depth pins the location of the shelf break. In areas where the shelf is wide, onshore geodetic constraints on seismic coupling is limited and could be advantageously complemented by considering the location of the shelf break. Subduction margin morphology integrates hundreds of seismic cycles and could inform seismic coupling stability through time.&lt;/p&gt;