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Made available in DSpace on 2014-06-12T18:05:08Z (GMT). No. of bitstreams: 2 arquivo6822_1.pdf: 7684044 bytes, checksum: 17f0703c4f48825060cad19862e748ce (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2006 / A Bacia da Paraíba está localizada na faixa costeira dos estados de Pernambuco e da Paraíba, entre o Lineamento Pernambuco, em Recife-PE, e o Alto de Mamanguape, ao norte de João Pessoa-PB, abrangendo uma área de aproximadamente de 5.300 km2 em sua porção emersa. É uma bacia de margem continental passiva e está inserida na porção leste da Província Borborema. Estruturalmente é rampa assentada discordantemente sobre o embasamento cristalino, apresentado subdivisão em três sub-bacias: Olinda, Alhandra e Miriri, de sul para norte, respectivamente. Na sua Seqüência Clástica Inferior foram reconhecidas duas parasseqüências, a basal, siliciclástica e de ambiente continental, constituída de conglomerados e arenitos grossos a finos e a outra, calcissiliciclástica, de ambiente transicional-marinho, constituída de siltitos arenoargilosos fossilíferos, arenitos calcíferos fossilíferos, e um horizonte fosforítico interpretado como um hardground, que representa a Superfície de Inundação Máxima-SIM. A Parasseqüência Siliciclástica foi depositada sobre a rampa interna num Trato de Mar Baixo através dos sistemas de leques aluviais e rios entrelaçados e a Parasseqüência Calcissiliciclástica foi depositada sobre a rampa internaintermediária, através de sistemas lagunares e praial/planície litorânea num Trato de Sistema Transgressivo. A correlação entre os poços de sondagens identificou um marco estratigráfico/radioativo no horizonte fosforítico através das perfilagens com raios gama. A bioestratigrafia mostrou idades entre Coniaciano-Maastrichtiano Inferior, determinadas por nanofósseis calcários, palinomorfos e foraminíferos. Os 􀄯18O e 􀄯13C marcaram bem a SIM e as elevadas temperaturas no Campaniano Superior. A evolução da bacia mostra que ela é tardia em relação às congêneres, devido ter sido o último elo entre os continentes africano e sul-americano

The Lower Triassic Sinbad Limestone Member of the Moenkopi Formation has produced minor amounts of oil in the Grassy Trail Creek field near Green River, Utah and is present below much of central Utah including the recently discovered Covenant field. Superb outcrops of this thin (15 m), mixed carbonate-silicilastic unit in the San Rafael Swell permit detailed analysis of its vertical and lateral reservoir heterogeneity. Vertically, the Sinbad Limestone comprises three facies associations: (A) a basal storm-dominated, well-circulated skeletal-oolitic-peloidal limestone association, (B) a storm-dominated, poorly-circulated hummocky cross-stratified siliciclastic/peloidal association, and (C) a capping peritidal cross-bedded oolitic dolograinstone association. Eleven microfacies are present in 14 measured sections within the Sinbad Limestone. Lateral variation is most pronounced in the upper part of the basal limestone where storm-deposited beds pinch out over a lateral distance of one kilometer. Otherwise, individual beds and microfacies display a large degree of lateral homogeneity and regional persistence. Diagenesis is strongly controlled by microfacies. Diagenetic elements include marine fibrous calcite cements, micritized grains, compaction, dissolution and neomorphism of aragonite grains, meteoric cements, pressure dissolution, and dolomitization. The paragenetic sequence progresses from marine to meteoric to burial. Marine and meteoric cements occlude much of the depositional porosity. Hydrocarbon-lined interparticle and separate vug (largely molds) pores (1-5%) characterize the skeletal-oolitic limestones with permeability ranging from 0-100 md. Low permeability/porosity characterizes the middle silicilastic unit. The best reservoir qualities (permeability 400 md) occur in portions of the dolomitized oolitic grainstones that form the upper 2 to 3 m of the Sinbad Limestone. Fracture analysis of the studied area indicates a strong NW-SE trend. Fracture spacing is associated with lithology. Fracturing of limestone possibly displays a higher dependence upon bed thickness and microfacies type. The degree of dolomitization controls and increases fracture spacing while siltstones display more closely spaced fractures. The basal limestone unit is an oil storage unit, medial siltstones are flow baffles/barriers, and the dolostone caprock is an oil flow unit. If good connectivity through fractures can be obtained between the dolostone and limestone units, the Sinbad Limestone has potential to serve as a reservoir. This study will not only aid in future Sinbad exploration, but will serve as a model for parasequence-scale intervals in thicker mixed carbonate-siliciclastic successions.

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