Pm technical brochure

TECHNICAL BROCHURE

PETROMARKER

The PetroMarker CSEM system is a vertical-vertical, time domain system.

Both transmitter and receivers are stationary during data acquisition and only the transmitter is tethered to the vessel.

PetroMarker is the only CSEM system that works efficiently throughout the exploration and production cycle, from grassroots exploration, through feasibility study and 4D. The receiver-transmitter geometry, plus 6,000 Amps of source power gives unprecedented target sensitivity to up to 5,000m below sea floor.

The fact that the grid is completely flexible allows for widely spaced exploration grids, more tightly spaced feasibility grids and totally geometrically repeatable 4D patterns.

Because the transmitter is not towed, but rather carefully placed on the seafloor, the PetroMarker system may be used safely and efficiently in areas of busy seafloor infrastructure.

the vessel.

PetroMarker is the only CSEM system that works efficie production cycle, from grassroots exploration, through

PETROMARKER

Software PetroMarker uses several inversion and forward modeling codes including the Scripps code MARE2DEM and the 3D LawrenceBerkeley time domain code.

There is an ongoing 4D CSEM code research project to develop software to invert the differences between baseline and future surveys.

Electric field diagrams from different CSEM systems

Horizontal CSEM System

PetroMarker Vertical-Vertical System

PETROMARKER

PetroMarker’s proprietary datalogger

Fifth Generation Receiver System The latest receiver system has now been redesigned, manufactured, fully tested and used on projects.

The latest receivers have a 32 bid ADC and extremely low noise floors, approaching 1 nV/ in the field and 0.5 nV/ for shorted input tests.

Receiver with field data

There are currently 25 receivers. The receivers can be dropped to and recovered from the seafloor autonomously, leaving only a small amount of sand and wood behind. They may also be lowered to the seafloor by a shipborne winch, giving replacement errors of less than one meter.

Receiver data with shorted input

PETROMARKER

Square Wave from pulse generator

Transmitter System The transmitter system consists of three main components; a pulse generator, two electrodes constituting the dipole antenna, and an A-frame for launch and recovery of the electrodes.

The dipole antenna consists of two steel electrodes, where one electrode is suspended a given distance below the survey vessel, and the other electrode sits on the seabed.

Both electrodes are designed to have large surface areas, to efficiently push strong DC currents into the sea water.

The return current goes from the lower to the upper electrode through the sea water, and the electric field associated with

this flow of current induces a primary field which propagates into the subsurface.

The pulse generator is basically a DC current generator which is capable of creating square bipolar pulses with sharp ramp-ups and cutoffs. It is the rapid cutoff from maximum output current to zero current which induces the secondary field that propagates from the subsurface back to the receivers.

The a-frame is designed to ease launch and recovery of the dipole electrodes.

On a regular basis, two such transmitter systems, each capable of an output of up to 3,000 A, are employed simultaneously.

PetroMarker AS /// HQ: Notberget 12 /// 4029 Stavanger /// Norway Rep. Office: Bryggegaten 9 /// 0250 Oslo, Norway