The DynaPump is a proprietary, computerized crude oil pumping system. The surface-mounted hydraulic system uses electronic sensors, hydraulic equipment and computer monitoring for the purpose of extracting oil in an extremely efficient manner from both shallow and deep wells. The system's advantages over other technologies include low acquisition cost, high reliability, low maintenance requirements, light weight, portability, fast installation, automatic diagnosis of well operations, automatic diagnosis of pump operations, automatic flow control, long stroke, differential speed up and down, lower installed power requirement, and remote computer control.
The system consists of two main components: the pumping unit and the power unit. The power unit drives the pumping unit and is the control center of the system. It consists of a computer-controlled system with radio modem, solid-state electronics, motor controllers and hydraulic pumps. Pumping units and power units are sized to meet the specifications of each well.
Systems are now being used in California, Texas, New Mexico, Utah, Colorado and Venezuela. They have set records for total flow for a hydraulic system and are capable of producing total flow in excess of 10,000 bbl of fluids per day. In some cases, the system has more than doubled oil production for customers, with a payback of two months.

Pumping unit
The pumping unit mounts over the wellhead and can be tracked back to accommodate a workover rig. Its main components are a hydraulic cylinder, which provides the lifting force (1,800 psi maximum design pressure); a pulley system, which transmits the lifting force to the rod string by wireline hanger; and a gas reservoir, which acts as a counterweight and has no inertia. Units can be supplied in a range of sizes to match the well's maximum
rod load; this is equal to the sum of the rod-string weight and fluid-
column load.

Power unit
The power unit provides the driving force and control for the pumping unit. It consists of a computer system for pump control, receiving input data for pump operation and logging of well data; a hydraulic pump system, with either electric or gas-engine driven pump drives; and a control and communications center, with solid state electronics and motor controllers. Solid-state electronics are employed throughout to ensure maintenance-free operation. The communications system transmits well and pump performance data by modem, radio transmitter or direct phone line. Wireless communications diagnostic modules indicate failures of the well or the machinery.
The lightweight control system has variable speed up and down, an automatic pump-off controller (speed adjusts to flow conditions) and a flow capacity ratio of 5:1. The control system has the ability to change speeds, stroke and many other parameters either on site or remotely.

Lower costs
The acquisition costs of the system are typically about one-half or less than that of traditional technologies. The system can be installed and operating in less than 3 hours, which lowers installation costs. The system reduces lifting costs in a number of ways:
50% or lower power consumption per barrel of fluid pumped;
Ultra-long stroke means fewer strokes per minute (SPM). Fewer strokes mean fewer parted rods. Also, the SPM can be reduced, resulting in less work for the system and less wear on the rod string and pump;
When using a natural-gas engine drive system, it requires one third the horsepower rating of a matching beam pump driver, producing an energy savings of approximately 70%; and
Automatic pump-off control.

Operating characteristics
Longer strokes generally equate to longer life for the bottomhole pump (BHP) and rod string. This longer stroke (called the equivalent beam pump stroke) allows for larger flows at deeper horizons, as the stroke losses at the bottom are fixed; hence every increase of stroke at the surface is a net gain of stroke at the bottom.
The stroke can be changed manually by hitting a few computer keys, or it can be configured to change automatically in response to factors related to well loads. Other rod systems operate with a fixed stroke.
The variable speed system is both automatic and manual. Each up or down speed is independent of the other. In high-friction wells (deviated wells or heavy-oil wells), the speed down is limited, and if the speed up and down are the same, it entails a severe limitation in the speed up, hence a production limitation. The variable-speed system adapts to the maximum speed down, without having a loss on the speed up.
In deeper wells, volumetric efficiency of the BHP becomes low and declines further with wear and tear. As slippage only occurs going up, when the system runs faster up than down, the time ratio is changed (25% up and 75% down is possible) and slippage is curtailed. The efficiency of the BHP can easily grow 50% or more.
Independently adjustable accelerations and decelerations are completely independent of the speeds. As a consequence, system overloads or underloads because of accels or decels are extremely small (a beam pump goes from 40% over gravity to 100%). The peak polished rod for the system is much lower than for a beam pump (never more that 5%).
The system loads barely change with speed, as the accels and decels remain unchanged. The same DynaPump pumping unit and the same pump and rod design can be supplied with different power units for production flexibility.

Applications
In terms of depth and flow, system performance is comparable to the submersible pump. Other rod pump technologies do not have the rod capacity or torque to reach those flows. The operating energy savings are substantial, especially considering that these devices run 24/7. The ratio of power consumption at equal depth and flow runs from one fifth to one tenth.
At the middle range of flows and depths, the system is an economical alternative to beam pumps and gas lift. Compared to the beam pump, an increased flow (when available or necessary) creates a much better cash flow together with fewer parted rods, lower power consumption and low capital expenditures.
Compared to gas lift, doubling well production is typical, together with cutting dramatically gas consumption and eliminating the classic winter problems.

Field examples
Coalbed methane field. Increasing gas flow was hampered by a high fluid level. The existing 160-beam unit with a 74-in. stroke was running at 9 SPM and not able to pump off the well, which limited gas production to approximately 100 Mcf per day. A system was installed with a 20-hp power unit. The system has more than twice the stroke length of the previous beam pump. With the increased load capacity of the system, the BHP size was increased to 2 in. Within 30 days, the well was pumped off and gas production increased to 300 Mcf per day.
Converting from gas lift. Gas production profits were continuously being compromised by the use of gas lift on a substantial number of wells. The use of submersible pumps would not prove profitable based on the projected production. BHP sizing for a conventional beam unit would not meet the flow requirements and ensure rod string life. A system with a 100-hp power unit was installed. The system has much slower accelerations and decelerations and is adjustable, thus increasing rod string life. In addition, the structure rating of 60,000 lb allowed for a larger BHP. The installation more than doubled the oil production.
Load feedback. A west Texas well had a polish-rod clamp slip. This resulted in a BHP position that was lower in the barrel, and pounding started. The system immediately detected the loss of load and stopped. This prevented continued damage to the BHP. Other rod-pumping systems would have continued pounding, resulting in costly repairs.
Barrel damage. A New Mexico well had damage to the barrel near the bottom of the stroke. The system's variable stroke length enabled raising the bottom-stroke position. By moving the bottom-stroke position up, the scored position of the BHP was avoided. The well was able to continue producing while waiting on repair.
For more information, visit www.dynapumpinc.com.

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