British Petroleum

Key Features

Monitoring of 33 offshore wells.
Dual redundant data transmission paths using a passive network.
Use of existing data transmission link to shore.
Data Visualization using Zencus Web View via the BP corporate intranet.
Data analysis with remote alarms and diagnostics.

Zencus Scope of Work

Site Survey and radio transmission tests.
Detailed engineering design.
Equipment and SCADA software supply.
Field installation.
Commissioning.
Client training.

System Architecture

The data transmission architecture on the three BP offshore platforms can be summarized as follows;

Zencus wireless pressure transmitters installed directly on existing wellhead connections.
Zencus wireless temperature transmitters installed directly using non-intrusive thermowell fittings.
Receiver Gateway installed in the control/communication room with dual redundant receiver modems and antennas.
PC with Zencus PC-View Visualization software installed in the control/communication room.
Gateway connected to the existing BP Process Network (TCP/IP) for transmission to the BP shore terminal at Dimlington.
Zencus Data Server with OSI ECHO data historian installed at Dimlington with Zencus WebView Data Visualization software and link to the BP corporate intranet to provide real-time data, diagnostics and alarms to remote users.

Southern North Sea Offshore Well Monitoring Project Overview

To date three offshore platforms located in BP's southern North Sea (SNS) asset have been instrumented by Zencus as summarized below;

Field / Platform	Date Installed	No. Wells	No. Instruments
West Sole Alpha (WSA)	April 2007	9	36
Amethyst ST2	May 2008	10	37
Amethyst ST3	August 2008	14	45
Total to Date	To Present	33	118

The primary objective was to monitor Well Integrity; typically Annulus A, B & C pressures and wellhead temperature and deliver the data to the Well Engineer's desktop in real time. A practical constraint was the cost and logistical problems in laying cables from the platform control rooms to the instruments located in the well cellar deck.

BP Westsole Alpha - Data Transmission Block Diagram

Due to platform congestion there was no line-of-sight between the instruments and the receiving antennas located outside the control room and there were concerns that reliable wireless data transmission would not be possible. However, detailed site-survey tests and subsequent system performance demonstrated that the data transmission was reliable with 99.5% reliability when transmitting every 30 seconds.

Note; 434 MHz was selected as the radio transmission frequency rather than 2.4 GHz as the lower frequency has the following advantages;
- Signals penetrate solid obstacles e.g. blast walls.
- Signals "bounce off" steel pipe-work and equipment, thus forming a passive mesh network.

The Zencus Westsole Alpha installation won a BP International Helios award commendation in 2007.

The West Sole Alpha (WSA) installation has been running for more than two years without any system downtime or need for instrument re-calibration.

Typical Field Installations

Successful Wireless Data
Transmission from Remote
Satellites to central Control
Room BP Westsole Alpha
(click to enlarge)

Pressure Mono Transmitter
Installations on Satellite Wells
(click to enlarge)

Zencus Pressure Mono-Transmitters
retrofitted to an existing installation
(click to enlarge)

Successful Wireless Data Transmission from Remote Satellites to central Control Room BP Westsole Alpha

Pressure Mono Transmitter Installations on Satellite Wells

Zencus Pressure Mono-Transmitters retrofitted to an existing installation