Diapir's Characters, Distriution In Myanmar Sea And The Relationship With Reserviors

There are lots of diapirs characteristics in Myanmar Sea and adjacent regions.Distribution is range,formation mechanism are complex.It may be a major effect for possession of hydrocarbon accumulation.Myanmar Sea and adjacent area belong to active continental margin.It is located at the south of the Eurasian plate, the north of the Indian plate-Australian plate,the west of the Pacific plate, and the north of west Bengal.It is adjacent to Bangladesh and the west of Sumatra, The eastern of Myanmar Sea and adjacent regions close to southern Thailand and Malaysia, the north of Myanmar Sea and adjacent regions are adjacent to Mishmi thrust fault zone, namely the Indian plate with the Eurasian plate, and the Pacific plate intersection. From structural dynamics and kinematics characteristic analysis, the India plate tectonic belt is located at the north and north-east to oblique subduction and strike-slip faults under double mechanism control of active continental margin development structure formation. According to the characteristics of structural evolution, Myanmar Sea and adjacent regions are divided into five tectonic belts, and nine depressions. Myanmar Sea and adjacent regions diapirs developed in the special tectonic environment where India plate, Eurasian plate and the Pacific plate intersect, so diapirs are more complex,and the research is extremely difficult.This paper mainly applied seismic data,logging data and drilling material to research the diapirs features and the diapirs distribution in combination with regional geological background material,sedimentary material and faults system features of this area Comprehensive geometry, kinematics and dynamics characteristic of diapirs to solve diapirs formation mechanism, Finally concluded that the relationship of diapirs and hydrocarbon accumulation.Myanmar Sea experienced passive continental margin, transitional continental margin and evolution to today's active continental margin three stages, It is formed phase iii tectonic evolution patterns.Complex tectonic background formed Mixed media diapirs in accretionary wedge, volcanic island of diapirs magmatic hydrothermal and Mud diapir of back-arc depression of back-arc basin the Andaman sea. The accretionary wedge diapirs is mainly distributed section A4 block,Rmree island, and the A7 block,M2 block,M5 block and M8 block in the Arakan's coast area. The Andaman sea-nicoba accretionary wedge section diapirs distribute in M2 bloc, M5, M8 block.In these areas,Rmree island, A4 block, and A7 block, M5 block, M8 block are belong to cold diapirs, cold diapirs of the accretionary wedge are 500km long. In different tectonic settings, cold diapirs width of stope have some differences between that.The main feature of diapirs is mud volcano or mud diapirs and mixed medium diapirs.Role in the formation of diapirs have many Pierce types and create branch type, tortoise type, and cylindrical structures.especially M2 block formed many fault block structures.Accretionary wedge diapir's mechanism is complex. Mixed media diapirs is India Plate produced during subduction of magmatic hydrothermal and seawater, molten material, the connection basaltic magma and magma mingling of abnormal role in the formation of diapirs, is found in the research of complex diapir. Accretionary wedge diapirs type is respectively the low energy and low-rising uplift, medium energy turtle on high-energy pierced and augmentation of diapirs, even development a lot of mud volcano. Accretionary wedge basin basically has two sets of source rock developmental horizon. Deeper Eocene formation is mudstone and shallow Miocene is mudstone. It is found oil and gas in the Accretionary wedge, but already exploration to closely related with the structure of diapirs oil and gas found few of the tectonic belt. If Accretionary wedge slope basin block-M2,A7 block hydrocarbon source rocks thickness, good types, but larger organic matter maturity is low, the universal in immature-low in mature stage, to the detriment of hydrocarbon reservoir into the transformation and the formation.Volcanic island of magmatic hydrothermal diapirs are distrubuted in volcanic island-arc bring,segmentating back-arc depression before Arc former and back-arc depression. In research area, they are mainly distributed between the M2 and M3 blocks, M5 and M6 blocks, M8 and M9 blocks and so on. Volcanic island has high temperature hot fluid of strong energy. Volcanics penetrate overlying strata. The top formation overlying on diapirs nuclear lies shallow in the earth, which are upper Miocene and Miocene strata. Diapirs is divided by tensional fracture with bending profile and "cabbages" structure in profile. The area around diapirs nuclear form incline with Miocene formations foilding and forming a series of somillar folid. Myanmar sea with volcanic island arcs depression before the west is eastern of back-arc basin, the Andaman sea back-arc depression.the tectonic belt's new series-Miocene wudaoliang sedimentary of gradually is thinner and mainly develop pierced type diapirs. Magmatic hydrothermal origin is the founction of diapirs magma body up top Joe emplacement and puncture of surrounding rock or magma vertical rise caused by unstable gravity effects or and lateral extrusion. Rock has no hyperplasia phenomenon.Shearing action between magma rises and relative decline in surrounding form incline in surrounding rock. Diapirs rock often submit pour water droplets shape and form a series of piercing structure.Back-arc depression diapirs is mainly distributed in the back-arc basin, the Andaman sea back-arc depression north, close to the M1, M3, M4, M6, M7, M9 etc block of motor class bay area, characterized with gas chimney mud diapirs. The diapirs developed in the tectonic belt strikes almost NS, has large qualities and various sizes. The biggest mud diapirs measures 125km from north to south and 5.7 km from east to west, the smallest 13km and 4km. Among them, M3, M4 block has smaller amount but higher mud diapirs, but Ml block is on the contrary.Mud diapirs are vertically distributed in Cretaceous,Eocene,Oligocene,Lower Miocene,Middle Miocene,Upper Miocene,Pliocene, Quaternary, formation.The formation mechanism of Back-arc depression diapirs is diverse. The major controlling factors is high temperature gradient, strike-slip faults effect, the Irrawaddy handling of sediment deposition and the result of comprehensive effect of gravity and lateral stress. The three different diapirs of Myanmar Sea and adjacent regions have great impact on the oil-gas accumulation, with respectively fifferent degee of influence on hydrocarbon, source rocks, reservoir,layer etc. Hyperplasia wedge of diapirs has bigger destructiveness on hydrocarbon accumulation, and poor accumulation factors, which promote the formation of oil-gas accumulation with its source rocks from back-arc depression. Back-arc mud diapirs has dual effect on oil-gas accumulation. Open fractures developed from diapir caused massive hydrocarbon dissipation, but in structural belt where fracture development is weak good reservoirs are formed. The structure of diapirs mainly follows the real are strike-slip faults along the strike-slip faults development, development of the size of monarch. Diapir distribute mainly along the Sagaing strike-slip faults, and the scale of the diapir developed along the Sagaing strike-slip fault is large. Back-arc depression diapir development focus areas, with the mataban Bay and Irrawaddy sediment transport and strike-slip movement of Sagaing faults and abnormal high temperature thermal fluid effects. Therefore, diapir and its associated faults control oil and gas accumulation depression effection of the back-arc basin, the Andaman Sea...