American Oil and Gas Reporter - February 2015 - 48

tion of hydraulically fractured wells;
* Liquids unloading; and
* Pneumatic controllers and pumps.
EPA's studies of leaks from onshore
natural gas operations have determined that
methane and VOCs are emitted at all stages
of the oil and gas value chain, but they also
found that most leaks occurred at a small
number of components and sites. EPA believes that portable analyzers can effectively locate and measure leaks from production sites, while optical gas imaging and
ambient/mobile monitoring may be used
in tandem to detect leaks along transmission lines. EPA's studies indicate that the
cost of implementing leak detection technologies generally is far greater than the
cost of repairing leaks.
In its evaluation of methane emissions from compressors, EPA concluded
that methane leaks from reciprocating
compressors-particularly from the nose
gasket and rod packing-increased as the
equipment aged and wore. Among the possible controls for reciprocating compressor emissions that EPA identified are periodic replacement of rod-packing systems,
or implementing technologies such as
vapor recovery units that capture emissions
and route them back to the compressor or
another process.
For centrifugal compressors, EPA asserts emissions can be controlled by dryseal designs, which generally produce fewer emissions, require less maintenance, and
are more energy-efficient than wet-seal
units.
Completions, Production
EPA acknowledged that data available
on emissions from oil well completions
and recompletions were incomplete, but
studies indicated methane emissions during well completions often occurred during flow back. EPA believes that reduced-emission completions and completion combustion devices can be effective
in oil wells that produce associated gas.
The agency also is investigating other technologies for controlling emissions during
completion, including liquefaction of natural gas, natural gas liquids recovery,
gas reinjection, and using flow-back gas
for on-site power generation.
EPA's 2014 greenhouse gas inventory
states that liquids unloading processes
comprise 14 percent of emissions from the
natural gas production sector. However,
studies have asserted that the majority of
these emissions are caused by a small number of facilities and are driven primarily
by the duration and frequency of the
practice.
Industry has developed several technologies to remove liquids from wells and
reduce emissions during liquids unload48 THE AMERICAN OIL & GAS REPORTER

ing. Using plunger lift is the most common, although the efficiency of these devices varies significantly, depending on
how the system is operated. EPA stated that
artificial lift, velocity tubing, and foaming
agents also had shown promise as "zero
emission" solutions for blowdown operations.
Finally, EPA found that pneumatic-controller emissions comprised 13 percent of
the oil and gas sector's methane emissions.
Studies indicate that multiple variables affect emissions from pneumatics, although
it is not yet well understood which variables are most significant. Differences have
been observed based on device design,
service, the region of installation, production volume, supply gas composition and
pressure, and operational settings. However, studies indicated wide variations in
emissions even among devices of similar
type, installation, and service.
EPA believes several techniques can reduce emissions effectively from pneumatic controllers. Low-bleed, gas-driven controllers can replace high-bleed, gas-driven controllers in most, but not all applications. Where electric power is available,
instrument air systems can replace natural gas-driven pneumatic controllers, and
eliminate methane and VOC emissions.
Zero-bleed, mechanical, and solar-powered
controls can replace continuous-bleed
controllers in some applications. Pneumatic pump emissions, which frequently occur during venting, can be mitigated by using instrument air or electronic pumps.
In response to these white papers,
several industry groups criticized EPA for
overstating total methane and VOC emissions from their sectors, and exaggerating
the economic and environmental benefits
of requiring emission controls and mitigation. These criticisms may presage future
legal challenges to the new standards because EPA is required to consider the costs
of controls for source categories in setting
performance standards for methane under
the Clean Air Act.
In contrast, environmental groups argued the white papers provided evidence
sufficient to justify direct regulation of both
new and existing sources of methane. Case
law suggests EPA has discretion to determine the timing and priorities of its regulatory agenda, including the timing of issuing existing-source regulations.
Additional Agency Actions
The administration's methane strategy
anticipates several other federal agencies will issue methane-targeting regulations this year. The administration said the
BLM would release its long-awaited rule
to reduce venting and flaring on federal
and tribal lands.

BLM originally committed to issuing
a draft of this rule, known informally as
Onshore Oil and Gas Order No. 9, by November 2010, but delayed action until April
2014, when it issued an advanced notice
of proposed rule making and invited input
from industry stakeholders and environmental groups. BLM is expected to issue
a draft of the rule during the first quarter
of this year, and intends to integrate its regulations with EPA's new performance
standards.
Based on comments from stakeholders
and BLM's responses, the new rule may
draw on state initiatives targeting venting
and flaring. In February 2014, Colorado
adopted rules requiring oil and gas producers to limit methane emissions by conducting routine equipment inspections at natural gas wells and compressor stations, and
promptly completing any necessary repairs. Additionally, producers must take
steps to reduce natural gas venting by, for
example, installing low-bleed pneumatic
controllers. As noted, EPA believes these
types of technologies can be effective in
identifying leaks.
In addition to Colorado's leak detection
and repair program, Wyoming and North
Dakota have enacted new venting and flaring policies that could inform BLM's rulemaking efforts.
The methane strategy also states that the
Pipeline Hazardous Materials Safety Administration will propose additional safety standards for natural gas pipelines that
will reduce methane emissions as co-benefits.
EPA's Office of Inspector General
provided a set of recommendations for reducing methane emissions from natural gas
distribution pipelines last July. The inspector general urged EPA to partner with
PHMSA to address methane leaks from a
combined environmental and safety standpoint, establish performance goals, and
collect data on distribution sector emissions to determine whether future regulation would be appropriate. The report also
recommended that EPA collaborate with
state utility commissions to develop and
expand policies that encouraged mitigat-

Coming In March
AOGR looks at the benefits of using multiwell pad automation to optimize asset performance, the capabilities of new midstream infrastructure
projects in resource plays, and retooling in the U.S. refining sector in response to growing domestic oil production.

American Oil and Gas Reporter - February 2015

Table of Contents for the Digital Edition of American Oil and Gas Reporter - February 2015