PerForM™ Permanent Seismic Monitoring System
PerForM is a flexible tool for integrating seismic and production measurements, with power and data transmission via a common cable. Signal transmission is fibre optic and redundant, allowing integration of seismic nodes (3C or 4C) with pressure, temperature and other measurements.
PerForM™ Permanent Downhole Seismic
PerForM is a seismic acquisition system for permanent installation inside a well. Up to 120 levels of 4C seismic nodes consisting of 3 geophones and a hydrophone can be deployed in the well. The system is used for both seismic survey data acquisition and microseismic monitoring.
The data acquired is used to improve static and dynamic reservoir description, map fluid movements and fronts for improved reservoir management and to improve quality and resolution of 3D and 4D surface seismic. Continuously monitors micro-seismic activity for subsidence and fracture detection.
The downhole instrumentation consists of seismic nodes and one or more pressure / temperature gauge nodes with options to extend system for other production related measurements. The data acquisition rate can be up to 0.25 msec for seismic surveys, with pressure and temperature sampled at 1.0sec. A READ proprietary and patented mandrel ensures that the seismic sensors are clamped to casing and decoupling from the production tubing after installation.
Originally developed for offshore platform installation, the system can equally be used on land and in offshore subsea installations. Preferably, wellhead penetration is made with a minimum of 1 fibre optic and 1 coax electrical penetrators. However, if optical fibre penetration is not available or not allowed, PerForM can be installed using just 1 coax electrical wellhead penetrator. In either case optical fibres must be available in the umbilical or other cables to transmit the data optically to the recording unit at surface.
Pressure / temperature measurements
PerForM comes with a single pressure / temperature gauge as standard. Several gauges, dual gauges and other production related measurements such as flowrate, density etc. can be added. Each measurement is interfaced to the system as if it was a seismic node and the data output to the control room and/or separate reporting and recording systems at surface. Third party gauges and measurements can be interfaced, as long as the output signal is digital and an iterface protocol can be established.