Distributed fiber optic sensing (DFOS) solutions are poised to empower the upstream oil and gas industry. With DFOS, the entire fiber can become a sensor, enabling monitoring on a truly distributed basis. They promise the cost-effective mapping and monitoring of wells, pipelines and reservoirs. In short, DFOS can provide the industry with clearer sight. Examples of this include: dangers posed to pipelines, progress during hydraulic fracturing and the integrity of a thermal enhanced oil recovery project.
WHAT IS DISTRIBUTED FIBER OPTIC SENSING?
DFOS utilizes the backscatter from light pulses directed down a fiber optic cable. As light travels down the cable some of it is reflected back off the glass and structure of the cable; this forms a “backscatter” that makes its way back up the cable to the source.
It is the interpretation of distortions to various reference points within this “backspatter spectrum” that enables the monitoring of temperature, acoustics and/or strain affecting the cable. Backscatter occurs down the entire length of a fiber optic cable. As a result, every single part of the fiber can become a monitoring device: a sensor. Changes to surrounding conditions can thus be identified, localized and interpreted.
Pipeline outages due to theft, accident or vandalism can all be anticipated using DFOS. By using the fiber as an acoustic sensor one can identify in real-time what is happening near the pipeline. Using this intelligence a rapid response unit can be deployed and the threat averted.
This makes for compelling economics because pipeline outages can cost millions of dollars on a daily basis, creating uncertainty in supply and driving oil price speculation. Across Asia and the Middle East, Visiongain estimates that a new distributed acoustic sensing solution adds between .15 percent and .2 percent to the total cost of a pipeline.
The pipeline monitoring capabilities of DFOS are invaluable to an oil and gas industry struggling with security issues. Nigeria, Yemen and Mexico are but a select list of countries that suffer pipeline issues. Mexico’s Pemex reported the discovery of 2,614 illegal siphons on oil, gas and petroleum product pipelines in 2013, whilst Chatham House has estimated that 100,000 barrels of oil per day (bopd) was lost in Nigeria in the first quarter of 2013 due to theft. In Yemen, attacks on pipelines are an all too frequent occurrence.
So costly is this insecurity that risk analysts are concluding that sources such as shale oil are better bets for investment and it is possible to link this rationale with divestments in Nigeria. In early 2014, it was reported that Shell was off-loading its 30-percent stake in four Nigerian oil blocks that produce circa 90,000 bopd; in June 2013, Chevron put five of its blocks up for sale; and in December 2012 ConocoPhillips sold its Nigerian unit for $1.79 billion.
Pipeline security issues serves to increase oil prices, but also provides a compelling case for DFOS uptake.
Oilfield services providers are constantly striving to optimize completion techniques and hydrocarbon recovery. The application of hydraulic fracturing techniques to shale formations has pushed US crude oil production to its highest level since 1990 and decoupled the gas price from oil on the North American continent.
To further this trend, DFOS can provide the data needed to help companies move away from a homogenous approach to hydraulic fracture treatments. Benefits include, but are not limited to: identifying and observing fluid movements; noting packer performance; identifying leakages; and an improved understanding of stimulation placement.
SEISMIC ACQUISITION AND PERMANENT RESERVOIR MONITORING
Enhancing recovery from mature reservoirs is fast becoming a core part of the oil and gas business. Visiongain estimates that in 2013 2.94 million bopd were produced using enhanced oil recovery techniques.
When the cost efficacy achieved with pipeline monitoring is transferred to seismic acquisition DFOS should plug into this theme. The main barrier to existing 4D seismic acquisition techniques (seismic data gathered over time) is upfront cost. Geophone and nodal technology are often viewed as prohibitively expensive given the uncertainty risk attached to any enhanced recovery benefits.
The first steps toward using DFOS as an alternative are being taken. In February 2014, Optasense signed an agreement with Petroleum Development Oman (PDO) to supply a 4D seismic solution that will use its distributed acoustic sensing technology.
TOO MUCH DATA?
DFOS solutions produce data in the terabyte volumes every week. Gathering data in such vast volumes is a challenge from a storage point of view, but the value of such quantities is also questionable. Designing software to interpret this data should enable the amount gathered to be reduced – programmers will highlight points within the data of importance for analysis and thus storage. However, there will likely remain a mentality within the industry that future software development could yield insight and, therefore, that collecting the maximum amount of data should always be the default setting.
SOLUTION UPTAKE AND INDUSTRY OPPORTUNITY
In 2012, the 10,000 kilometer (6,100-mile) mark was passed for pipeline monitored using DFOS. Meanwhile, the solution has been used for many years as a temperature sensor.
Today, the main thrust for research and development is hydraulic fracture monitoring and seismic data acquisition, which represent the two biggest market opportunities.
The areas in which DFOS can provide solutions – well, pipeline and reservoir monitoring – are consequential for oil & gas pricing and the direction of E&P investment in three core ways:
- Pipeline integrity and security affects the global oil price and the CAPEX budgets of oil majors (pipeline monitoring);
- Hydraulic fracturing of shale has transformed the upstream industry and the fortunes of American oil and gas (well monitoring);
- Enhanced oil recovery is increasingly crucial as companies seek to make the most of existing reservoirs (reservoir monitoring).
With its capabilities in each of these domains, DFOS looks set to become a piece of equipment with significant influence over the oil and gas industry’s future outlook and trajectory.