Pro-Fit Salt Water Disposal Plant Design
An Engineered Approach to Steady State Plant Design
INTRODUCTION
The oil industry of the past can be characterized as an aging traditionalist group
of companies trapped in their own paradigms. In 2014 the oil industry is
vigorous, and made up of younger, better educated, fearless, far more flexible,
imaginative, and aggressive professionals who have few if any paradigms. All
that is lacking now is the knowledge of what is possible and how to achieve it.
With water is at the forefront of most oil industry discussions today, managing
water is one of the more pressing topics. In 2014 the industry is using more
water than ever before in it massive frac jobs. Water sources are limited, and
water re-use is a hot topic.
In 2014 the industry produces over none times as much water as oil. All of that
water has to come from someplace and it has to go someplace when it is
expended. The common denominator is today’s salt water disposal plant, the
“SWD”. However, thousands of SWDs already exist today. Most are older;
unmanned, built before the advent of SCADA, and without an emphasis on oil
recovery or EBITA economics.
Hundreds of new SWDs are built every year. Many of these are built with a
focus on low capital cost and ROI, with income treated like an annuity. The
builders often copy other local plants rather than employing engineering
expertise. And still, they make money!
They do not, however, make near as much as they should!
The Pro-Fit™ SWD System attacks this issue with a vengeance, maximizing
performance, and increasing owner cash flow by at least 200%.
Pro-Fit™ is a patented SWD process and plant design. It employs only state-ofthe art components. Each component is selected to compliment the next and to
contribute to optimum overall plant performance. The result is a complete
system, engineered to generate maximum cash flow and the highest profitability
for the owner.
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THE PRO-FIT™ PROCESS
The Pro-Fit™ process was developed with three prime directives for any SWD plant:
1. Capture and sell every drop of available crude oil.
2. Clarify the water to the greatest extent possible within a controlled economic model.
3. Maximize disposal well life through automated fluid flow management in the plant.
The common denominator and the condition necessary to achieve them is the “steady state”
operation of the SWD Plant.
Since gravity separation is in play in all SWD Plants, the separation of oil from water follows the
physical laws of gravity separation. Chief among these is Stokes’ Law. Stokes’ Law quantifies
the separation velocity, or flow rate, of two or more separating fluids according to their physical
characteristics. Since dynamic separation has to do with flow velocities, enhancing separation
has everything to do with controlling the fluid flow, with the aim to achieve a steady state where
flow is constant.
Steady state is difficult to achieve in any SWD Plant. In 2014 most water is trucked from the
source to the SWD Plant in 130 barrel trucks. Trucks arrive at unpredictable intervals and
numbers. The water received into the SWD Plant from these trucks is totally unpredictable both
in terms of quantities or timing. This reality creates a real challenge for the steady-state design
of any SWD plant. The goal of achieving the constant flow of fluids in an ever changing fluid
flow environment is quite challenging, but it is far from impossible. The Pro-Fit™ System
achieves this goal!
To achieve steady-state in a SWD Plant, the inlet flow needs to be conditioned to a more
constant flow condition. To do this all intermittent inlet flows need to “buffered”. Buffering
flow rate changes can be accomplished by 1) dividing the flow, and 2) accumulating or storing
the inlet water in an intermediate storage facility. By accumulating the inlet fluid in “buffer”
tanks, the inlet flow rate peaks and valleys can be equalized using storage as a buffer to varying
rates so the effluent from the buffer tanks can be controlled at the desired and constant flow rate.
Next, with crude oil prices at or near $100/barrel, a primary SWD Plant process goal is to
separate, capture, and sell every drop of crude oil present in the waste water being hauled to the
SWD Plant. The first step in this process is to slow the flow rate of the inlet fluids as mentioned
above. This is first done by equally dividing the inlet flow into the inlet buffer tanks via a flow
dividing tank (aka DFSD™) so that the flow rate of the influent into any one buffer tank
downstream is a fraction of the total inlet flow.
The next step in this process is to design the buffer tanks so the influent stream in each buffer
tank distributes uniformly in the entire tank, thus further slowing the overall flow and
maximizing the retention time of the fluids within each buffer tank. Doing so obviously
maximizes the opportunity for separation. The result is a pre-separation of oil and water, where
some percentage of the oil entrained or dispersed in the water can and does separate in each
buffer tank. Since it is virtually impossible to achieve ideal retention time in buffer tanks, only a
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portion of the oil will separate there. As a key part of the Pro-Fit™ System flow distribution
internals are installed in every Pro-Fit™ System buffer tank to maximize fluid distribution.
Additionally, depending on the time that oil remains in the buffer tank, the crude oil may contain
various quantities of contaminants. These contaminants are defined by the term BS&W, an
acronym standing for “basic sediment and water”. For oil to be marketable, these contaminants
must be reduced to very low concentrations. The allowable concentration varies geographically,
generally in the 0.1% to 3% range, and averages 0.5% maximum.
Steady state is the key to removing the oil borne BS&W contaminants. So, the Pro-Fit™ System
uses smart level transmitters to detect the amount of oil in each tank, and to transfer it to oil
storage tanks where no dynamic fluid movement occurs. This level of quiescence maximizes
BS&W separation in the oil tanks, reducing BS&W levels to those acceptable to a crude oil
buyer.
The water leaving the buffer tanks is metered out of the buffer tanks by special low-shear liquid
moving pumps. These specialty pumps are designed to avoid the mixing energy necessary to
remix oil and water. These pumps move the buffered water, which entered the plant a various
flow rates, out of the buffer tanks at a constant flow rate, achieving the desired “steady state”
process condition. The water now flows in a steady state at a constant flow rate into an oil-water
separation system designed for the maximum steady state flow rate of the SWD Plant. This
separation system (aka HWSB™ Skim Tank) efficiently separates remnant crude oil from water,
automatically sending separated crude oil to the crude oil storage tanks, and sending the
separated oil-free water to a storage tank (aka surge tank) from which the water is eventually
pumped through a filter bank and on to the deep disposal well.
PRO-FIT™ “AUTO-OP™” AUTOMATION SOFTWARE
The entire Pro-Fit™ system is computer controlled. Pro-Fit™ operating software manages the
flow of fluids throughout the plant one these priorities:
1. Maintain the high pressure injection pump in a running condition whenever possible to
minimize deep well formation damages from a start-stop condition.
2. Maintain near-constant flow through the oil-water separation system within a narrow
band to optimize oil-water separation efficiency.
In order to maintain water flow through this highly dynamic plant the Pro-Fit™ automation
software manages the fluid flow through the plant under its many varying conditions. These are
typified by the descriptions below:

DAYTIME OPERATIONS
Trucks are employed to move water from its remote sources to the SWD Plant. Most of
this water hauling process occurs during daylight (normal working) hours, roughly from
sun-up to sun-down. Since each SWD Plant services a grouping of source facilities
within a given radius, truck traffic tends to group. This tends to happen in “activity
waves”. Each wave results from the natural traffic flow for trucks going to the source,
picking up a load of water, driving to the SWD Plant, dumping the water, and returning
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to the source for another load. Trucks tend to typically arrive at SWD Plants in three
waves; one in the morning, one around noontime, and one in the late afternoon.
As these trucks begin to arrive in the morning the Pro-Fit™ automation software
maximizes the throughput through the SWD plant to keep the buffer tanks as empty as
possible. During any one wave of truck traffic, the varying inrush rate of water exceeds
the constant disposal rate of water, so the buffer tanks gradually fill up. Sufficient tanks
are included in the Pro-Fit™ process design so the tanks normally never fill completely.
As the noontime wave occurs, the Pro-Fit™ software continues to manage total plant
throughput at or near maximum. However, after the noontime wave the Pro-Fit™
software begins to automatically throttle back the outflow, managing the buffer tank
storage space to just accommodate the late afternoon wave without overfilling any buffer
tank, but allowing the buffer tanks to reach the near-full condition. This “managing”
means that during the afternoon hours the disposal well pumping system is throttled back
to achieve the ideal near-full storage condition desired after the final wave in the late
afternoon.
From the conclusion of the late afternoon final wave event until the next morning wave
the next day, the Pro-Fit™ software slows the rate of fluid transfer from the buffer tanks
through the separation (HWSB™) system and on to the surge tank. It also reduces the
disposal pump to a software-determined rate so the buffer tanks are near empty when the
first wave of the next day begins. The surge tank is the last tank in the system to empty,
providing an additional buffer against the likelihood of a no-water-flow plant condition
which would trigger the undesirable disposal pump system shutdown.
In unusual conditions resulting from higher than normal water haul truck activity
triggered by new well flowback water hauling 24/7 events, the Pro-Fit™ software
determines that the wave events are not occurring normally, and adjusts accordingly to
maximize throughput through the SWD Plant 24/7.
Finally, the Pro-Fit™ software alerts the owner and his staff in the event of any unusual
event. If a component malfunctions, Pro-Fit™ reports it electronically via SCADA
communications so a technician can be dispatched pre-advised of the failure point so he
travels to the SWD Plant site with the knowledge and parts he needs to execute the
necessary repairs.
Perhaps the most important unusual event for the SWD Plant owner is the custody
transfer of his crude oil. This is the cash cow if his plant, generating the majority of the
plant’s gross and net income. The Pro-Fit™ software allows the owner to permit such
custody transfers via an encoded remote owner input, and alerts the owner and his staff in
the event any unauthorized movement of plant crude oil is attempted.
CONCLUSION
The Pro-Fit™ SWD Plant Design and Pro-Fit™ software program combine to produce
SWD plants which operate themselves to minimize human interfacing, maximize oil
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recovery and oil quality, take effluent water quality to the highest possible level to avoid
disposal well plugging, and allow for automatically maximized daily water throughput
for complete SWD plant utilization under widely varying and reasonably unpredictable
conditions.
The result is a smarter plant with maximized cash flow in a 21st century environment
where manned operation is unnecessary.
ABOUT THE DEVELOPER OF THE PRO-FIT™ SYSTEM
Bill Ball is the founder and owner of HTC, Inc. He has a long history of oilfield plant
and separation system design development, which when coupled with his vast oilfield
experience and career portfolio, make him one of the industry’s leading SWD Plant,
Plant Automation, and Separation system authorities today.
After his university studies his career began in a very challenging 1,000,000 b/d
waterflood operation where he was responsible to evaluate and improve the
performance of all surface facilities. Through this hands-on effort, he learned the
modifications that help improve process efficiency, and those that do not. In the 50
years since Bill has accumulated a lifetime of knowledge and experience in oilfield
separation, and now is the named inventor in several related patents.
The culmination of this work are patents covering the Pro-Fit™ SWD Plant Design and Automation
System, and components like the HEGB™ (high efficiency Gunbarrel), the DFSD© De-sanding, Degassing, Flow Splitting Tank, the HWSB© Skim Tank, and the Pro-Fit™ SWD Plant design. These and
other unique components achieve the highest level of separation and hydraulic efficiency known to exist
in any design, and make the Pro-Fit™ Plant design the best in the industry. The results are an
unparalleled quality and quantity improvement in the effluent streams, and the most immediate ROI for
investors in these technologies and intellectual properties.
Today, HTC, Inc. is one of the industry’s leading low-cost surface facilities design firms. Bill surrounds
himself with like minds. He and his team of seasoned veterans specialize in salt water disposal (aka
SWD) plant, flowback water treatment plants, crude oil processing and dehydration plant designs, and
many other endeavors worldwide.
HTC affiliates blanket every field of engineering discipline making HTC a full service firm capable of
complete turnkey designs.