The ability to control well flow from anywhere signals another milestone in the evolution of total field and reservoir optimization.

The petroleum industry is entering the era of intelligent well completions. This era is heralded by a new generation of intelligent production tools and monitoring systems to measure and record how efficiently individual wells are operating.
Developers are coming up with remotely operated measurement and control systems that bring it all together under the heading of "intelligent reservoirs."
Debuting at this month's Society of Petroleum Engineers Annual Conference and Technical Exposition in New Orleans, La., Schlumberger Oilfield Services' Automated Artificial Lift (AAL) Service, coupled with proprietary software, will allow oil company production and reservoir specialists to monitor - and operate - surface and subsurface elements of artificial lift systems from practically anywhere in the world in real time. As an example, officials with Schlumberger's Well Completions and Productivity segment said that with the new service, an oil company engineer in Houston, Texas, can observe flow data from a well thousands of miles away in Indonesia. If necessary, the engineer can adjust valves and chokes, both surface and downhole, and submersible pumping systems to optimize production from that well. The engineer then can watch the flow effects the adjustments have produced.
By combining hardware, measurement data, IT systems and software tools, operators can collect the data necessary to modify flow parameters in remote, high-cost or critical wells. In the end, this ability permits optimum reservoir development and helps reduce risks associated with equipment problems, particularly downhole. This mitigates the need for numerous well interventions, expensive downtime and deferred production costs. Such capabilities, Schlumberger said, put the operator in a position to add value to single wells or entire fields.
Designed primary for newly completed or recompleted wells, the AAL Service can be used to monitor and control production in fields already equipped with gas lift or submersible pumping systems. This includes multilateral wells. Elements of the service also can be used to monitor and control production from naturally flowing wells in advance of artificial lift.
Software part of solution
Lance Fielder, manager of artificial lift integration with Schlumberger's Well Completions and Productivity segment, said the company's proprietary InterAct two-way communication system allows use of any computer with a standard Web browser to gain secure access to the well or wells equipped with the surface and downhole sensors and controls. The software, provided when the system is installed, arms the user with the remote-control capability.
On the hardware side, the service's individual surface and downhole measurement components are mostly technology that exists, said Fielder. The communication system can be made up of components from Schlumberger, Wireless Matrix - a Canadian company Schlumberger works with to provide remote connectivity - or in some cases a customer's existing SCADA system.
"Most of the pumps, gauges and flow controllers upon which the service relies are already being used, either individually or in various combinations, in existing wells around the world," he said. "But the AAL Service closes the loop, since it permits secure, real-time reservoir monitoring and control from anywhere in the world." This could range from a computer at the well location to those at Schlumberger's offices to machines at any of the operator's offices, even on other continents, he said.
Schlumberger is so confident about the value of the AAL Service that while it will use traditional commercial models, it will also propose performance-based incentive models that will allow it to share in the benefits of the service when results exceed preassigned metrics, Fielder said.
Field tests prove service
Elements of the service already are being used to optimize production in several wells around the world, said Fielder. One case involved a multilateral well in the United Kingdom. The well is equipped with a tubing-retrievable flow-control valve and a submersible pumping system with gauges that sense pressure, temperature and flow rate in real time. These downhole data are transmitted, via the pump power cable, to the client and Schlumberger's offices via the InterAct Web system.
"Production specialists use these data to analyze and adjust the flow-control valve to optimize production from the two producing lateral wellbores," he said.
Several components of the service have been used in other North Sea wells, Fielder added. In one well in the Norwegian sector, downhole gauges and flow-control valves were adjusted from the surface to control early water breakthrough and gas production from three independent zones. Initially, there was an unanticipated rapid increase in gas production while flowing two of the zones. Having the ability to control the zonal inflows allowed the operator to set production from each of the three zones individually. Additionally, the wellbore control is used to control the gas influx so that it efficiently gas-lifts the oil-producing zones, further maximizing the oil production.
Although the monitoring and control adjustments for the North Sea wells were conducted from nearby field offices, they could just as easily have been done from an office computer thousands of miles away, Fielder added.
Artificial lift plans included earlier
The dominant raison d'être for introduction of the AAL Service is the growing demand by operators for artificial lift systems that increase oil output and economic return, said Peter Goode, segment president.
The average size of new discoveries has fallen from some 200 million bbl in the 1960s to about 50 million bbl, said Goode. And while the new reservoirs will contribute much to overall oil supply, alone they will be insufficient to meet future demand. Existing reservoirs will require optimization as well, in order to help fill the bill.
But new discoveries tend to be in remote basins far from a rich oilfield infrastructure, which increases development costs, he added. Because of the higher expenses involved, operators tend to consider the entire reservoir in field development planning. This shift in emphasis persuades them to include artificial lift requirements in the completion design, even before the well is drilled. It makes economic sense, he said. For a comparatively minor up-front cost, installation of an artificial lift system during the completion can result in earlier positive cash flow, which improves net present value and return on investment (Figure 1).
Goode said the AAL service is one of the essential components of a comprehensive, closed-loop process that optimizes well and field productivity and, ultimately, reservoir performance.