--> --> Abstract: Magnetic Anomalies Associated with Oil and Gas Fields, by D. Schumacher; #90987 (1993).
[First Hit]

Datapages, Inc.Print this page

SCHUMACHER, DIETMAR, Pennzoil Exploration and Production Company, Houston, TX

ABSTRACT: Previous HitMagneticNext Hit Anomalies Associated with Oil and Gas Fields

The presence of Previous HitmagneticNext Hit anomalies over oil and gas fields has been noted for several decades, but it is only in recent years that the phenomenon has been critically examined. Studies of geologically and geographically diverse regions show that (1) authigenic Previous HitmagneticNext Hit minerals occur in near-surface sediments over many petroleum accumulations, (2) this hydrocarbon-induced mineralization is detectable in high resolution, broad bandwidth Previous HitmagneticNext Hit data acquired at low altitude and with closely-spaced flight lines, (3) the Previous HitmagneticNext Hit susceptibility analysis of drill cuttings and near-surface sediments confirms the existence of the aeromagnetic anomalies, and (4) sediments with anomalous Previous HitmagneticNext Hit susceptibility frequently contain ferromagnetic minerals such as greigite, maghemite, magnetite, nd pyrrhotite.

The formation of Previous HitmagneticNext Hit minerals under conditions of hydrocarbon seepage is a very complex process and still poorly understood. The specific minerals formed depends on many factors, and the stability of these authigenic Previous HitmagneticNext Hit minerals is also variable. For example, non-Previous HitmagneticNext Hit species such as pyrite and siderite can be oxidized to more Previous HitmagneticNext Hit minerals, whereas some Previous HitmagneticNext Hit species can under highly reducing conditions be altered to pyrite or siderite.

The association between hydrocarbon seepage and the formation of authigenic Previous HitmagneticNext Hit minerals in the near-surface has important applications in hydrocarbon exploration. Aeromagnetic delineation of potential hydrocarbon accumulations is a rapid, cost-effective method for surveying and evaluating large areas. Although the discovery of shallow Previous HitmagneticNext Hit anomalies does not guarantee the discovery of hydrocarbon accumulations, it does identify areas requiring more detailed evaluation. Proper integration of near-surface Previous HitmagneticTop data with geologic and seismic data can improve exploration success and reduce development costs.

AAPG Search and Discovery Article #90987©1993 AAPG Annual Convention, New Orleans, Louisiana, April 25-28, 1993.