| Studies have shown that orogenic belt and foreland basin hydrocarbon reservoirs andmore to construct reservoirs mainly of times in different tectonic movements tend toform multi-phase structural traps, but also makes the tectonic movement superimposedto form very complex structures belly. Understanding of the transformation of the roleof nappe motion on the ground belly trap reservoir, and Structure superimposed impacton other aspects of the oil and gas conservation, will determine whether the region hasthe potential for oil and gas exploration. Therefore, in the overthrust structure with oiland gas exploration, we must first find out to belly structural characteristics, can bepreferred exploration targets. Longquan Mountain tectonic zone located between thewestern Sichuan foreland basin sag belt and foreland slope belt, belong to thruststructure, morphology and characteristics of the underground structure to figure outalso very important.In this paper, the previous data and geological information related to clarify theregional geological background and stratum situation, and use Xujiahe newhierarchical scheme comparison group division.Through the application of the theoryof fault-related folds, combined with outcrop data, seismic reflection characteristics,establish structural model. By logging data and hierarchical data，production ofsynthetic recorded. The use of the newly created structure model of two-dimensionalseismic work area，to explain the scope of work and analyze structural characteristics.Finally, from the hydrocarbon source conditions, reservoir conditions，trap conditionsand preservation conditions four aspects of hydrocarbon-bearing conditions evaluated.First, the main contents.1. By through-well seismic profile for horizon calibration, establish Longquanshanmain structure model.2. For the related seismic data structural interpretation to determine the basic form oflocal structures and fault relationships.3. Research Xujiahe T3x2, T3x4reservoir characteristics.Second, the major work done.1. The collection and collation more than70copies of basic geological informationand literature.2. Investigate the6geological cross-section, and draw up two sectional drawing.3. Interpretation of seismic profiles over1000km.4. Two tectonic modeling.5.Compiling the top of T3x2and T3x4structural map.Third, the main results and recognize. In this paper, the use of geological modeling and stratigraphic correlation techniques,re comparison against Longquan Mountain tectonic zone Xujiahe formation. On thebasis of the use of reprocessed seismic data establish to structural models, for theinterpretation of the relevant seismic data on Longquan Mountain tectonic zone. Themain points made about the results and recognize.1. Xujiahe division using the new program, on the Longquan Mountain tectonic zoneand adjacent areas have been drilling reclassified contrast. The focus on be drilled welllogging profile data of Xujiahe is relatively good condition of the LQS1wells andLQS6wells to contrast. From each well drilling system stratified results compared withthe original had varying degrees of difference, which LQS1Well the biggest difference,Xujiahe top sector pick up in this division rose in21.5m and Xujiahe group internaleach paragraphs are changes. Contrast LQS6new and the old hierarchicaldiff erences， mainly on changes in the T3x4and T3x6. In the old hierarchical, thethickness of T3x4segment is too large and T3x6segment small thickness in the oldhierarchical.2. By field survey work on the Longquan Mountain of east and west sides, have amore clear understanding on the fractures. Longquan Mountain east and west sideshave obvious rupture structural features. Fracture extends along strike does not havecontinuity, intermittent. Longquan west side fracture were developed with steep, northeast side of the fracture development Gaojiazhen Renshou steep zone, south of the townof Gao steep with no development. Longquan Mountain things on both sides of therupture disk steep growth with more than one place, in a different there are more thantwo or three places with steep growth. This phenomenon indicates that the presence ofnear-surface plate branch small faults on both sides of the main things LongquanMountain fault.3. Longquan Mountain tectonic zone Characteristics with "S" shape twist on theplane.LQS1well have a strong fracture role in the north, the ground is more typical andcomplete anticlines form, Structural style is characterized with recoil structure andstructure protruding West ward. LQS1well have the weak fracture role in the South, theground anticline obvious morphological, structural style is characterized by a forwardthrust structure.4. Combined with geological surveys and seismic data to Structural styles changeresearch, and establish in the two studies structure modeling. From14LQS112linestructure model look, tectonic style performance of reverse fault-bend fold. Thestructural style is the stepped or plow-like, decollement fault layer is located insideLeikoupo cream rock salt layer, the upper layer of decollement fault in the lowerJurassic shale section.14LQS111line structure style is positive and negative formsoverlay structure. The main fault structure located in the west wing and tendencies East,the secondary fault located in the east wing and the West tends to dip slowly, in thelower part of the secondary faults cross with Xujiahe on main fault.5. By comparison and explain，we were found to more than ten focused onLeikoupo formation of faults in the abdomen. These faults are reverse faults, mostlynorth east trending, and structural trend parallel or nearly parallel to the main fault (fault West Wing, East Wing tomography) developed in the structure of the wings,and extend parallel to each other between, they controlled the tectonic belt thedistribution rules of each local structures. West Wing fault, the east wing of the mainfault Longquan Mountain tectonic belt detachment fault, the larger, more disconnectedLeikoupo around layers, which are located in Longquan Mountain West Wing and EastWing tectonic zone, break up the surface. West Wing fault structure closer to the top,usually presents a fault, from south to north through the entire work area, extendingaxial direction is consistent with the structure. West Wing is a fault in the northernsection of the main fault, the control of the morphological structure of the northernsection of the Longquan Mountain tectonic zone, while the east wing of tectonic faultsform the main structural control of the southern section.The cross-section, in the West Wing fault structural zone off the northern section ofthe West Wing to the East Wing from the structure, the main structure of the entirecross-section oblique Longquan Mountain, from shallow to deep dip angle becomessmaller, the performance of " plow " fault or "L" type faults, and the composition of theEast Wing fault "Y"-shaped. Overthrust belt to belly up to3kilometers at its widestpoint, breaking away from the larger, the largest drop of about2000m, extends far,the survey area is about70km. East Wing tectonic belt in the southern section of thefault is the main fault, breaking away from the relatively smaller, the biggest drop onlyabout1000meters, but extends a large scale, extending parallel to each other and theWest Wing of the fault.6. Through research on Longquan Mountain tectonic zone of the reservoiraccumulation conditions think hydrocarbon source Longquan Mountain tectonic zonebetter conditions, it is advantageous of hydrocarbon migration to point to areas. Thetypes of T3x4and T3x6reservoir spaces have a dual nature of the medium, as crack–pore. Longquan Mountain tectonic belt have good regional cap and direct cover arecharacterized with a large thickness and wide distribution. Fault Zone to the east andwest sides of the preservation of oil and gas have some damaging effects, but thecurrent fault contact between the footwall stratigraphic analysis, fault seal better.Longquanshan structure has seen a long-term exploration, but failed to get an idealexploration results. Therefore, this study deepens the Longquan Mountain tectoniczone shall be home stratigraphic correlation and structural characteristics analysis,further to find a new favorable exploration zones in Longquan Mountain tectonic zonehas important theoretical and practical value. |
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