Watching the World Learn to listen to your reservoir

Reservoir management today is a hit-or-miss affair, leaving lots of oil and gas in the ground when fields are abandoned.

This is the view of Ian Phillips, lead engineer for integrated solutions at Halliburton Manufacturing & Services Ltd., Aberdeen.

Phillips told a London conference on Apr. 8 that the traditional approach to gathering reservoir information starts with geologists "vaguely probing around" to compile an initial picture of an accumulation.

Then comes drilling and more seismic surveying to get a clearer picture, and finally dynamic data can be gathered during development of the field.

"The problem with this," said Phillips, "is that we have most data available about the reservoir when it is of least value to us, beyond say 8-10 years into development."

But Phillips reckons new downhole tools, some under development and some barely at conceptual stage-but due to become available in the next 10-15 years-could change this.

Smart wells

Halliburton is working with Petroleum Engineering Services Ltd. (PES), Aberdeen, to develop a 'smart' downhole tool called Surface Controlled Reservoir Analysis & Management System (Scrams).

PES recently announced a first contract for the product with Shell U.K. Exploration & Production to use Scrams in 15 North Sea wells (OGJ, Apr. 7, 1997, p. 36).

The Scrams tool incorporates sensors that feed data to a downhole microprocessor, which sends data to surface and also can be used to adjust downhole conditions through inflow control devices.

Phillips said operators have a need to improve in-well data, which they can use to improve well maintenance: "Preventive maintenance doesn't enter into the equation at the moment."

Operators also need data from between wells, said Phillips, so they can improve understanding of what is happening in the reservoir and improve their response to changing conditions.

Enabling technology

Some enabling technologies are already available outside the petroleum industry and need to be brought in. Phillips cited optical fibers used in the communications industry and sonar used to track submarines.

"Between-well data is where the greatest potential is," said Phillips. "Operators want to understand reservoir fluid flows to enable them to wring the most value out."

Phillips said Halliburton is contemplating development of downhole acoustic sensors so operators can "listen to their reservoirs." Then they could manage reservoirs better and identify bypassed oil.

Using products such as Scrams, a typical 250 million-bbl field development could improve revenues by $500 million, said Phillips, through improving oil recovery by 10%.

Phillips envisions future well locations could be judged for potential data recovery as well as hydrocarbon recovery. Wells could be wired up after drilling, to monitor fluid flows across a field.

As a prophet, Phillips is aware of the difficulty of persuading the notoriously cautious petroleum industry. He told delegates: "I suspect having a conversation like this will be a lot easier in 10 years' time."