Exploratory Drilling Project – Phase 1

Monitoring of ocean currents


The monitoring was intended to register the ocean currents between the winter and summer seasons in Block Z-38, in order to have information on the sea current for the drilling campaign.

What are drifting buoys?

Drifting buoys are oceanographic instruments floating on the sea surface. This equipment is monitored by satellite, which allows knowing its location for the duration of the monitoring.

The real time position can be known thanks to its internal GPS. The direction and speed of currents can be obtained from the difference between two consecutively acquired positions.

Components and purpose of the drifting buoys

Two different types of drifting buoys have been used to monitor currents:


It is made up of: spherical surface float (drifter or buoy), sea surface temperature sensor, GPS for localization, Iridium system for communication.

This buoy is used to represent the paths of the surface currents since they are directly influenced by the wind.


It is made up of: spherical surface float (drifter or buoy), a drogue and a tether system, immersion sensor, sea surface temperature sensor, GPS for localization, Iridium system for communication.

It is intended to maintain the buoy in contact with the current and to attenuate the direct influence of the wind on the buoy.

Commencement of operations

Karoon ran information workshops from April 21 to 28, 2018, in Acapulco, San José, Punta Mero, Bocapán, La Cruz, Grau, Cancas, La Jota, Nueva Esperanza, Zorritos and Puerto Pizarro where they informed the community about the works that Karoon has scheduled as part of the exploratory drilling activities. As part of these activities, the community was informed of the monitoring of ocean currents to be performed during the winter and summer seasons.

Winter Monitoring:

Karoon commenced its operations by deploying 12 drifting buoys between June 5 and 9, 2018. Buoys were deployed around the structure of the future Marina 1X well.

Summer Monitoring

Following the scheduled activities, in 2019, the second monitoring corresponding to the summer season was performed, in which 12 drifting buoys were deployed between March 15 and 19, at the location of the future Marina 1X well.

Processing and interpretation of information

The company in charge of deploying the buoys was “Ekman Serviços Ambientais e Oceanográficos” from Brazil. Ekman analyzed and interpreted the data provided by these pieces of equipment during the winter and summer monitoring.

It was observed that both types of buoys showed a different typical path, and this behavior was expected since SVP-WOCE buoys are influenced by surface and sub-surface currents (15 m depth) and the DBI Sphere buoys are influenced by the direct effect of the wind and the surface current.

The results obtained from drifters are consistent with the appraisals and monitoring previously performed on the surface currents of the Tumbes Basin.