Page 95 - Intelligent Digital Oil And Gas Fields

64 Intelligent Digital Oil and Gas Fields

to perform real-time workflows because there can be a considerable time lag
to get the data from the remote facility. Further, because getting the data to
shore is so slow, only limited amounts are moved at reasonable speeds, with
the remainder coming on in a “batch” overnight. Many companies are now
laying fiber optic cables to alleviate the lag and improve bandwidth. Some
locations are even moving toward satellite communications (Fig. 2.13)to
improve data communication and asset collaboration. Companies are
employing collaborative work environments for production operations
onshore to monitor and control in real time (Chapter 8).
Another evolving trend for these assets is the increased power of DCS
and historian systems. These systems regularly have the capability to deploy
multivariable control and predictive analytics hosted directly on the control
platform.

2.2.4 Unconventional Assets

Unconventional assets are uniquely fit for the DOF. These assets are newer
fields with many wells that are drilled and produced from centralized pads, so
more DOF infrastructure can be applied economically. The well production
does not lend itself to traditional modeling and field planning tools, like res-
ervoir models and nodal analysis, but data-driven models can be used appro-
priately to manage wells. For example, unconventional wells move rapidly
through their life cycle, going from natural flow to artificial lift in months.
This means unconventional fields have more data available and need more
data-driven workflows. As these fields are developed on multi-well pads, a
high degree of instrumentation can be centrally installed and the asset can
have local control capability. Most equipment has solar panels to drive
long-life batteries. They use produced gas to power valves and instruments,
and have some local control devices.
Local control devices have become much more powerful and easy to use.
Remote terminal units (RTU) with embedded control capability are widely
applied. A newer technology, programmable logic controllers (PLC), is
quite powerful yet easily programmed and is being used more frequently
in unconventional assets. PLCs can now be programmed with graphical-
based languages (as opposed to the old ladder logic) and can include
advanced capabilities, such as supporting multivariable predictive control
of devices without requiring a gateway-connected computer.
Wells in these assets typically have some form of well pad separation and
flow measurement as described. They typically include tubing, casing, and