DAS/DTS/DSS/DPS/DxS - Do We Measure What Adds Value?

摘要

Inwell measurement of rates and ratios do not allow operators to proactively control flow into the well. For intelligent fields there is a growing need for tools that enable engineers to 'see' further into the reservoir in order to adjust and/or change the flow control strategy as required. From a reservoir management perspective the most value can be achieved when implementing intelligent flow control systems coupled with surveillance tools. Hence, this study presents a way of defining a fit for purpose surveillance strategy that can be coupled with active flow control systems that facilitates the optimisation of the recovery efficiency. A dynamic simulator was used to analyse and determine a monitoring strategy that provides the most cost effective method of understanding various phenomena occurring within the reservoir, such as water/gas encroachment. The intention of the study was to determine if the data set currently obtained is sufficient enough to provide a deep understanding of the reservoir. The dynamic simulator modelled the temperature, saturation and pressure changes and the post-processer was used to derive corresponding changes in resistivity and acoustic properties. The change in temperature was important to model in order to study the parameter for its surveillance value as well as to capture thermal effects on reservoir fluid properties and geomechanical properties. The electro-magnetic and acoustic properties were calculated using a well-known formulae; resistivity was derived by inverting the Archie equation. Results from the study were used to specify what the surveillance tools should measure and what detection distance would allow operators to proactively adjust the flow control devices/valves in order to maximise the value of the development. Sensitivity and optimisation analysis was conducted to obtain the distance of investigation required by the surveillance. The study demonstrated that a simple 1-way coupling gives representative estimations of electro-magnetic and acoustic properties over field production time. This will be able to assist in determining which methods of surveillance can be used over the life of the field assisting in recommending a suitable data acquisition strategy to extract maximum value from the tools available; DAS/DTS/DSS/DPS/DxS, EM, seismic and other methods. Simple 1-way coupling is often enough to estimate the change with suitable accuracy to assess feasibility of various surveillance techniques. DAS could have an application in continuous cross-well tomography to follow the flood front; this subject is to be studied further.