Case Study by Shell E&P, The Netherlands and LIOS Technology GmbH, Germany
Presented at: Intelligent Wells Asia 2006 - 29-30. August 2006, Kuala Lumpur Malaysia
The oil and gas production industry faces continuously the challenge to optimize the production and reduce operation cost further. Following these motivations also new technologies and operating practices were adopted and/or developed. For a decade permanent optical in-well monitoring systems are gaining more-and-more acceptance in up-stream oil and gas production operation. However, so far mostly high-end and therefore usually complex – mainly deep-water wells – were the focus for these so called intelligent completions. High investments for the surface equipment, installation complexity, and the lack of standard tools for efficient data gathering and analysis were the main reasons for the general hesitation towards this technology; a major breakthrough is still awaited.
In a co-operation between Shell International Exploration and Production (SIEP) and LIOS Technology GmbH (LIOS) the feasibility and economical added value of permanent downhole temperature sensing have been successfully demonstrated in a number of recently deployed on- and offshore projects in Brunei. This paper presents the generic design and implementation of an exemplary case study for permanent DTS downhole sensing of low-cost land and offshore-wells. The entire scope of equipment and architecture from the well site to the office is taken into account with a view on fit-for-purpose, commercially sustainable, and cost-effective technical solutions for the end-user, the asset owner.
Right from the beginning of the oil industry people wanted to know more about the reservoirs they were exploiting. Thus having a more sound understanding about their reservoir behaviour and obtaining knowledge how to optimize the recovery of the hydrocarbons. As it was - and still is - impossible to look directly into a reservoir other ways to obtain information about the reservoir needed to be investigated. Direct surface measurements are helpful and still required today but downhole sensing became quickly an important topic for reservoir monitoring. The first sensors were for pressure measurements, then temperature, until nowadays micro-sensing images a whole ground section in 3D. Due to temperature observations along the borehole, a relatively easy measurement, a lot of information can be derived such as water- or gas-break-through. When e.g. observing water injectors in the warm-back-phase one can find the producing zones, hence this kind of information has a major impact. The advances in fibre optics, packaging and the experience gained over the last 5 to 10 years enabled the industry to deliver low-cost Distributed Temperature Sensing (DTS) systems. An additional factor was the further development of industry standards and electronics enabling to build an architecture that allows data flow from the well to the Production Technologist’s desk.