Underwater Gliders for Oil & Gas Exploration

Abstract

The occurrence of migrating near-surface hydrocarbons provides strong evidence for the presence of an active petroleum system, as well as valuable information on source, maturity, and migration pathways. The detection and characterization of natural seepage in the water column is therefore critical to de-risking hydrocarbon plays at a very preliminary stage of an exploration program. From this fundamental premise, we developed a project that aimed at providing an innovative solution for the direct detection of natural seeps using underwater gliders. Dedicated Oil & Gas sensors were implemented and a glider survey was designed to detect natural leaks of hydrocarbons following various scenarios. Here, we present the results of a gliders campaign launched at the end of 2017 in a deep offshore area. Two subsea gliders were deployed during 20 days to prove their navigation ability and the capacity of the sensors to detect natural leaks of oil and gas. The campaign was combined with the simultaneous acquisition of satellite images enabling the delineation of natural oil slicks at the sea surface in near real-time. The glider sensors collected many measurements including temperature, salinity, dissolved oxygen, chlorophyll but more interestingly liquid and gas hydrocarbon compounds. Vertical pipes of hydrocarbon fluids imaged by the gliders correlate well with the location of active known seep sites. Perhaps more impressively, dissolved hydrocarbons seems to be trapped in underwater layers in relation with strong contrasts in water density.

AAPG Datapages/Search and Discovery Article #90332 © 2018 AAPG International Conference and Exhibition, Cape Town, South Africa, November 4-11, 2018