Abstract
A new approach to reservoir monitoring using permanent sensors is outlined which employs the use of optical fibre preinstalled on the completion across the intervals of interest. Using optical fibre it is possible to obtain an accurate measurement of well temperature every metre along the producing interval at regular, sub-hourly, time intervals over the producing life of the well. Although temperature is not, in itself, a direct measurement of flow, well performance, water cut or gas breakthrough all do produce quantifiable thermal responses. These responses, combined with continuous monitoring allow identification of producing zones and rapid evaluation of production variations without the need for well intervention.
The paper will outline how optical fibre can be installed into a range of completions and well types. Real well examples are used to illustrate how distributed temperature monitoring can be used to for reservoir monitoring. These illustartions include monitoring gas lift mandrels, cross flow on shut-in, water breakthrough and monitoring flood rates in watered out intervals using the temperature of injected water as a thermal tracer.
The results demonstrate that pre-installed optical fibre is an effective real time method for monitoring wells and thus facilitates the optimisation of reservoir performance.
