Mathematical modeling applied to the analysis of magmatic intrusions thermal influence in Paraná Basin

This paper has the objective to present equations capable of generating one-dimensional models that permit to quantify the thermal influence caused by igneous intrusions. In Paraná Basin, the petroleum systems were great influenced by igneous activitiesin which they as presented by a thick lava effusion, a large number of dykes in the entire sedimentary section and various levels of sills intruded in stratifications in order to provide thermal energy for organic maturation. Thus, a better understanding of how and how much the intrusions affect the generation of oil and gas is extremely necessary since the knowledge related to the effects of intrusions in such atypical petroleum system is still insufficient. The obtained results show: the thermal influence caused by igneous intrusions is much higher than that proposed in the literature; the presence of multiple intrusions, based on the oil and gas window considered and as a function of it thickness, causes between them, unfavorable thermal influence to the generation of hydrocarbons in small distances and favorable thermal influence in large distances

MATHEMATICAL MODELING APPLIED TO THE ANALYSIS OF MAGMATIC INTRUSIONS THERMAL INFLUENCE IN PARANÁ BASIN

This paper has the objective to present equations capable of generating one-dimensional models that permit to quantify the thermal influence caused by igneous intrusions. In Paraná Basin, the petroleum systems were great influenced by igneous activities in which they are presented by a thick lava effusion, large number of dykes in the entire sedimentary section and various levels of sills intruded in stratifications to provide thermal energy for organic maturation. Thus, a better understanding of how and how much the intrusions affect the generation of oil and gas is extremely necessary since the knowledge related to the effects of intrusions in such atypical petroleum system is still insufficient. The obtained results show: the thermal influence caused by igneous intrusions is much higher than that proposed in the literature; the greater the number of intrusions and the thicker they are, the thermal influence is unfavorable at short distances and favorable at large distances

EVOLUÇÃO MAGMÁTICA DA INTRUSÃO BÁSICA NO POÇO 1UN30 E SUA INTERAÇÃO COM O ARENITO ENCAIXANTE, NA PORÇÃO NORTE DA BACIA DO PARNAÍBA (N E NE DO BRASIL): Magmatic evolution of basic intrusion in the well 1UN30 and its interaction with the enclosing sandstone, in the northern of the Parnaíba Basin

This work was developed as a result of petrographic, chemical and litogeochemical analysis of the 1UN30 well, drilled in the Parnaíba Basin. The petrography indicates that the igneous rock has glomeroporphyrytic texture and essential mineralogy of plagioclase and pyroxene with olivine and opaque minerals as accessories. The sandstone is a quartzarenite to subarkose with framework of the quartz, K-feldspar and opaque minerals, and interstices filled by tremolite and clay minerals. The igneous rock, by litogeochemical, is an intraplate tholeiitic basalt. Analysis of MEV pointed the clay minerals as belonging to the illite-smectite group and identified minerals of chlorite group. Through the textures and chemical analysis of the grains, two phases of plagioclase formation are identified. The most calcic phase occurs as corroded and zoned core with thick sieve textured. The other consists at the edges of corroded cores or in isolated crystals, zoned and with fine sieve texture. It concludes that the rock was formed by four evolutionary events: the first phase of crystallization; rapid decompression during rising of the magma chamber; mix with a warmer and rich in calcium magma; and the second phase of crystallization. The interaction with the magma formed tremolite and clay minerals in the sandstone, maintaining the anterior sedimentary aspect, in a process called contact diagenesis.Este trabalho desenvolveu-se através dos resultados das análises petrográficas, químicas e litogeoquímicas do testemunho do poço 1UN30, perfurado na Bacia do Parnaíba. A petrografia aponta: a rocha ígnea como de textura glomeroporfirítica e mineralogia essencial de plagioclásio e piroxênio, com olivina e minerais opacos acessórios; o arenito como quartzo arenito a subarcóseo com arcabouço de quartzo, K-feldspato e minerais opacos, e interstícios preenchidos por tremolita e argilominerais. A rocha ígnea, pela litogeoquímica, é um basalto toleítico intraplaca. Análises em MEV no arenito apontaram os argilominerais como do grupo ilita-esmectita e identificaram minerais do grupo da clorita. Pelas texturas e química dos grãos, identifica-se duas fases de formação de plagioclásio. Uma mais cálcica ocorre como núcleos corroídos, zonados e de textura peneira grossa. A outra consiste nas bordas dos núcleos corroídos ou em cristais isolados, zonados e com textura peneira fina. Conclui-se que a rocha foi formada por quatro eventos evolutivos: primeira fase de cristalização; descompressão rápida, durante a ascensão da câmera magmática; mistura com magma mais quente, rico em cálcio; e segunda fase de cristalização. A interação com o magma formou tremolita e argilominerais no arenito encaixante, com preservação do aspecto sedimentar prévio, em um processo denominado diagênese de contato