WELL CONTROL / INTERVENTION

Intelligent well interface standardization (IWIS)

An industry panel is actively seeking additional participation in completing important standards to help operators, service companies and vendors promote and perfect this important new technology

IWIS aims to lower the overall cost of implementing and operating "Intelligent (or Smart) Well" technology. It will open up more opportunities for operators to effectively implement these promising evolving technologies and greatly improve the way wells are monitored and optimized. All parties stand to benefit – oil companies and service companies from the reduced cost of providing real time well data to users, and suppliers from an increased hardware and well-service market.

Introduction. Due to the number of suppliers of downhole / subsea equipment, and possible methods of interfacing such equipment, there are potentially thousands of possible configuration permutations. Clearly, this is not an ideal situation. Imagine if the same situation applied to PC and ancillary equipment manufacturers and there were this many possible connections to the ports at the back of your computer! This is the situation that operators / equipment providers face during a typical subsea field development, leaving them with large costs for interface development / manufacture.

IWIS is an important industry initiative that addresses this issue. Its aim is: "To assist the integration of downhole power and communication architectures, subsea control systems and topsides by providing recommended specifications (and standards where appropriate) for power and communication architectures, and other associated hardware requirements."

The resulting integrated systems should allow operators to implement more downhole "smart" equipment in a timely and cost-effective manner, using off-the-shelf components for installations. Improving compatibility should also eventually benefit reliability and transparency (for diagnostics). The IWIS Industry Panel, currently comprising 17 operator and service sector companies, will assist in this process of integration by steering project initiatives and sharing best practices that benefit the industry as a whole.

Clearly there are proprietary interests at stake in the quest for a standard. The objectives of IWIS are championed by the operator subgroup within the Industry Panel, Table 1, but are now led by a steering committee comprising one member from each subgroup (operators, subsea vendors, downhole vendors). Rather than seeking to impose solutions on the industry, the panel instead aims to facilitate these intercompany discussions so as to reach mutual agreement on recommended specifications.

Ultimately, the aim is to draft a revision to ISO 13628 (Petroleum and Natural Gas Industries – Design and Operation of Subsea Production Systems) Part 6 (Subsea Production Control Systems). As many vendors as possible are encouraged to contribute to the panel discussions and deliverables since it is these companies that will be in a position to implement the agreed-to standards. Vendors who play an active role in IWIS and contribute to defining an effective standard will be able to offer more technically / commercially attractive solutions to operators.

Background. At the end of 1995, a number of oil companies organized a workshop on permanent downhole instrumentation. This revealed the growing difficulties of equipment integration for operators as a result of increasing use of monitoring equipment and electric control devices – known when taken together and associated with full control from topside as "Intelligent Wells" – supplied by a plethora of vendors. It was therefore agreed to define standardized interfaces for data communication and power supply distribution, to minimize the effort required by operators and the service industry in introducing these new technologies.

During the kickoff workshop, a task force was formed, comprising Shell, Saga and Statoil, to initiate the "Intelligent Well Instrumentation Standardization" project (IWIS) – since changed to "Intelligent Well Interface Standardization", which was first promoted within the PEA (Production Engineering Association). The IWIS project had a final objective "to arrive at recommended practices to ensure compatibility in data and energy transmission for intelligent wells."

In March 1996, the task force presented the IWIS project to the participating oil companies: BP, Agip, Elf, Statoil, Saga, Norsk Hydro and Shell.

In the period 1996 – 1998, an outside consultant, TNO, was hired to suggest a common protocol to all downhole vendors. After extended technical discussions between all participants, it was admitted that due to harsh downhole environmental constraints and s0all likelihood of putting monitoring equipment from various vendors on a common cable, IWIS should rather focus on standardizing the subsea interfaces, such as Fig. 1. This was actually where most of the future concerns were.

Fig. 1. Example subsea installation with one tree and one subsea control module per well. The well is a Smart Well with several zones.

It was then decided to involve subsea vendors and begin the integration of subsea and downhole approaches to power and communications. In 1999, Phase 3 was launched under the title of the IWIS Industry Panel. Through 2000, the panel has met six times, Table 2. As already stated, the intention of the panel is to: 1) facilitate widespread industry acceptance / endorsement of the standard; 2) develop further specification recommendations with an emphasis on subsea integration; and 3) provide a focused forum to share experiences and concerns. Until mid-2000, IWIS was chaired by Shell.

Subsea IWIS specification. A key part in development of the Subsea IWIS spec is definition of a standard interface between the subsea control pod and the downhole system, Fig. 2. For this standard interface, a distinction is made between low-power and high-power, downhole systems. At the project kickoff in December 1999, it was agreed that these two areas would comprise the main focus of the IWIS Industry Panel.

Fig. 2. Subsea IWIS.

   Low-power specification. The first spec is for downhole gauges interfaced to a subsea control pod, the scope is limited to electrical specs dealing with power transfer and data communication, but this definitely represents the most difficult subject to tackle. Types of physical layers other than electrical, e.g., optical fiber, are not currently included.

   The high-power specification is aimed at a standard for interfacing power / communications of downhole architectures that support both measurement and downhole electric control equipment. The development of this specification standard requires evaluation of the intelligent well concepts, based on current and future equipment and subsea infrastructure requirements.

Current situation. All participants have agreed that the best way to achieve a concrete outcome, endorsed by all, is to issue a standard of reference – hence the decision to amend the existing ISO 13628. The four main areas being developed for the new "Interfaces" section of Part 6 of this standard are:

1. Data communication interface
2. Power supply delivery to downhole equipment
3. Packaging and mechanical interfaces, and
4. Reliability, testing and validation specs.

In recent workshops, panel members have been working on the details of these sections and are now in the process of writing the standard for official submission. Until the standard is fully detailed and officially released, it has been decided not to reveal its entire content. But to demonstrate the members’ commitment to innovation, and to conform to modern information technology practices, we can reveal that IWIS will recommend TCP/IP as the communication protocol of preference.

Subsea equipment manufacturers will be responsible for carrying TCP/IP to downhole equipment; downhole vendors will be responsible for bringing a TCP/IP interface to the subsea interface; and operators will be responsible for promoting this selection in their future calls for tenders and installations.

A roadmap has been selected to help achieve agreement in the power, physical and testing specs sometime in early 2001.

What’s next? Encouraging IWIS Industry Panel membership on a worldwide basis is the next step. To this end, the March 2001 meeting of IWIS will take place in Houston to provide easier access for Central and South American players.

IWIS has all the ingredients needed to achieve successful cooperation between all industry members. It is important that the results of this work be publicized widely within the industry. To this end, members are considering presentation of their results at the next SPE meeting, as well as other relevant exhibitions and conferences.

On the technical side, as soon as a standard for subsea IWIS is agreed upon – expected in early 2001 – it is intended that IWIS will move on to consider integration of surface systems such as DCS, SCADA and RTUs. Operators will benefit from an integrated system allowing office-based users access to real-time well data on the desktop or mobile laptop, and an integrated approach to surface and subsurface data transfer. This will eliminate the need for large numbers of dedicated system terminals.

To conclude, IWIS will ensure that downhole equipment is interfaced to the production control system through modern standards, leading to seamless integration between equipment of all parties. It will also make the situation much clearer in non-subsea wells.

Another tacit motivation for the work that is being carried out is the imperative for our industry to join the ever-growing number of industries that benefit daily from the tremendous progress in information technology.

Further information can be accessed on the IWIS website at www.iwis-panel.com. Anyone wishing to participate in IWIS, or to comment on any of the views expressed herein, should contact the IWIS Steering Committee: 1) Rob Baird, Shell International E&P B.V, Tel: 31 70 311 2630, E-mail: r.p.baird@siep.shell.com; 2) Sissel Halmoy, FMC Kongsberg Subsea, Tel: 47 32 287804, E-mail: sissel.halmoy@fmc.kos.no; 3) Stephane Hiron, Schlumberger, Tel: 33 1 4537 2316, E-mail: hiron@slb.com; or 4) the IWIS Industry Panel Secretary, Guy Woodall, OTM Ltd., Tel: 44 1483 598000, Fax: 44 1483 598010, E-mail: guy.woodall@otmnet.com.