2013 International Sucker Rod Pumping Workshop

Technical Presentations

/
Session I:
New Technology, Research and Development
/ Session Chair:
Mark Mahoney
Brian Ellithorp
Presentation 1 Title:
An Innovative Design For Downhole Gas Separation / Company(ies):
Don-Nan Pump & Supply
Author(s):
Jyothi Swaroop Samayamantula
Rick Roderick / Contact Information

Abstract:
Gas problems can cost a company valuable time, money, and resources. The presence of gas in the pumping zone causes various problems like gas lock, gas pound, and gas interference, resulting in reduced pump efficiency and pump failures. In order to overcome these problems, our in-house research team developed and patented an innovative design called the Don-Nan Gas Separator, which diverts the gas away from entering the pump intake and thus reducing pump failures and improving the pump efficiency. The major topics of discussion are:
1.  Review of the problems that are encountered in gaseous wells.
2.  Design and working principle of the “Don-Nan Gas Separator”.
3.  Effectiveness of the system compared with respect to fluid fall velocities and gas bubble rising velocities.
4.  Observed case histories and improvements in the pump efficiency.
Notes:
2013 International Sucker Rod Pumping Workshop
Technical Presentations
Session I:
New Technology, Research and Development
/ Session Chair:
Mark Mahoney
Brian Ellithorp
Presentation 2 Title:
Tubing Anchor Catcher Applications and Operation / Company(ies):
Don-Nan Pump & Supply
Author(s):
Jyothi Swaroop Samayamantula
Ricky Roderick / Contact Information

Abstract:
From the selection process to installation and continued maintenance, the Tubing Anchor Catcher (TAC) is one of the most important tools in achieving efficient pumping operation. The upstream oil and gas sector continues to evolve with new methods morphed from old methods as it pertains to artificial lift systems. While the people and parts continue to change, understanding the basic, yet important, aspects of TACs with relation to their applications, operational procedures, and tubing stretch is necessary. In covering the basics and importance of the TAC, the scope of this paper will expand on tubing stretch calculations, shear values, drag spring usage, troubleshooting, and other installation techniques.
Notes:
2013 International Sucker Rod Pumping Workshop
Technical Presentations
Session I:
New Technology, Research and Development
/ Session Chair:
Mark Mahoney
Brian Ellithorp
Presentation 3 Title:
Wear Resistant Coatings for Sucker Rod Couplings / Company(ies):
ExxonMobil
URC, CSR, EMDC, EMPC
Author(s):
Bo Zhao, ExxonMobil
T. Anderson, M. Chelf, B. O’Donnell (URC)
D. Ertas, T. Haque, H. Jin, A. Ozekcin, S. Rajagopalan (CSR)
J. Bailey (EMDC)
M. Wilson, F. Marzuka (EMPC) / Contact Information

Abstract:
The ExxonMobil Upstream Research Company and ExxonMobil Corporate Strategic Research investigated the use of coatings on sucker rod couplings to reduce friction and wear for step-out performance enhancements. As couplings reciprocate inside the tubing of a rod pump well, both the couplings and tubing may experience wear and eventual material failure. Reduction of coupling and tubing wear can therefore prolong the operating time of the well and result in economic savings due to fewer work overs, less well downtime, and reduced material replacement costs.
In this study, various diamond-like carbon (DLC) coatings were tested in laboratory tribometers. The results were used to select coatings for several three-month long field tests in a rod pump well. A control test was also conducted in the same well using standard spray metal couplings.
After approximately 4,500 miles of travel, the best coatings in the field trials were observed to remain largely intact and adhered to the couplings. The lower wear rates of the coatings reduced the overall wear to the couplings. Furthermore, an analysis of before and after tubing scans showed that the coated couplings were more “tubing friendly” than spray metal couplings.
Using the two top-performing coating chemistries, long term durability tests were conducted on eight newly drilled wells. Similar wells in this field had an average hole-in-tubing (HIT) failure rate of approximately every six months. The test wells with DLC coatings have been operating for 12 to 18 months before a HIT failure at the time of this writing, and some are still ongoing.
In summary, this study evaluated DLC coatings in laboratory tests and production field tests. The field tests showed the coatings to provide wear protection to the couplings and tubing. Based on the long term tests, the coatings may increase well uptime between HIT work overs by over 50%.
Notes:
2013 International Sucker Rod Pumping Workshop
Technical Presentations
Session I:
New Technology, Research and Development
/ Session Chair:
Mark Mahoney
Brian Ellithorp
Presentation 4 Title:
Success Flushing Coal Fines through Downhole Rod Pump Equipment / Company(ies):
ConocoPhillips
Author(s):
Elizabeth Kane / Contact Information

Abstract:
ConocoPhillips San Juan Business Unit has reduced the number of rod pump repairs, and improved rod pump performance in coal fines producing wells by pumping water flushes down the tubing or casing. Rod pump failures in these coalbed methane wells are most frequently a result of coal fines. Coal fines can restrict the flow of water into the pump, cause the pump valves not to seat correctly, or stick the pump’s plunger. These problems are worsened as water production rates in the basin decrease due to dewatering, leaving less water to carry coal fines through the pump. The flushes have been performed as preventative maintenance for the pump or to restore gas production lost due to an inefficient or failed rod pump. The success rate of the flushes is greater when the flush is done proactively, before the pump problem has caused a loss in gas production.
Notes:
2013 International Sucker Rod Pumping Workshop
Technical Presentations
Session I:
New Technology, Research and Development
/ Session Chair:
Mark Mahoney
Brian Ellithorp
Presentation 5 Title:
Gas Locked Pumps are NOT Gas Locked! / Company(ies):
Echometer Company
Author(s):
Lynn Rowlan
Ken Skinner / Contact Information

Abstract:
The definition of a Gas Locked Pump is both traveling valve, TV, and standing valves remain closed during the entire stroke because the pump is completely filled with gas. The traveling and standing valves open if pressure below the valve is greater than the pressure above the valve. Gas Lock occurs if the tubing pressure on top of the plunger is always greater than the pressure inside the pump chamber and if the pump chamber pressure is always greater than the wellbore pressure on the outside of the pump at the intake.
On the down stroke before the TV can open and discharge the fluids from inside the pump chamber into the tubing, then the pump must increase the pressure inside the chamber from the intake pressure to the discharge pressure. The primary stated reason for running a high compression pump is to avoid gas lock. But, gas lock is impossible because even with tight pump clearances enough slippage occurs during a few strokes to fill the unswept volume of the pump chamber with liquid. Pump slippage eliminates the need for a high compression pump. Gas Locked Pumps are NOT Gas Locked, because slippage past the plunger will fill the unswept pump volume. Once the plunger comes in contact with liquid on the down stroke a low compression pump will still open the TV and discharge gas into the tubing.
Pump gas into the tubing, then the tubing fluid gradient will become less, tubing pressure will be less, and more gas will become free. If enough gas is pumped into the tubing then the tubing can unload; and a back pressure valve may be required to control the light tubing fluid gradient and maintain pump action. Pump cards seen when gas lock is thought to occur usually show flat pump card having no pump action. The tubing is often blown dry and the classic shape of a gas compression curve of a gas locked pump is never observed.
Notes:
2013 International Sucker Rod Pumping Workshop
Technical Presentations
Session I:
New Technology, Research and Development
/ Session Chair:
Mark Mahoney
Brian Ellithorp
Presentation 6 Title:
Extending Downhole Pump Life 300% Using New Technology / Company(ies):
Muth Pump
Author(s):
Tom M. Walker
Garold M. Muth / Contact Information

Abstract:
Sand, whether formation sand or frac sand, is produced along with hydrocarbons and water from many wells. This sand can accelerate wear of the plunger and pump barrel, and can also cause the plunger to stick in the barrel. These problems may result in frequent pulling jobs and expensive pump repair costs.
The Farr plunger, a newly designed pump plunger and pull rod, has been tested during this past year in numerous oil fields in California. These tests indicate that the Farr plunger has the potential to reduce the pump wear and plunger sticking problems caused by sand production. This paper describes this new design, and the initial results of the field trials
Notes:
2013 International Sucker Rod Pumping Workshop
Technical Presentations
Session II:
Design, Automation, Optimization, Challenges
/ Session Chair:
Norm Hein
Presentation 1 Title:
Improving the Reliability and Maintenance Costs of Hydraulically Actuated Sucker Rod Pumping Systems / Company(ies):
HRPI
Author(s):
Walter Phillips / Contact Information

Abstract:
Hydraulically actuated sucker rod pumps have been around since the 1940's but have not received a widespread adoption or acceptance on the order of beam pumps, ESP's or PCP's. This is in no small part, due to a reputation of high maintenance costs and frequent failures. Innovations in hydraulically actuated sucker rod pumps, with a keen insight for the oilfield environment, have helped improve reliability and reduce maintenance costs. Among these improvements are the elimination of persistent external hydraulic leaks, a long-stroke capability, and a simplified control system. The instrumentation and control of the hydro-mechanical system is accomplished with an innovative method for determining both polished rod position and load based solely on the hydraulic fluid dynamics. This eliminates any sensors, or points of failure, at the wellhead. Vast improvements in control and data acquisition have greatly reduced the failure rates of hydraulic sucker rod pumping systems by automatically responding to adverse conditions. By allowing operators to remotely interact and troubleshoot the system, a finer grained level of optimization can be achieved by closely matching the wells inflow to the production rate. In some down-hole failure cases, such as a stuck pump, a unique advantage of a hydraulic system allows the operator to attempt unsticking the pump by overloading the polished rod. Although this procedure is not always successful, it does provide a last resort that may save the cost of pulling the well.
This procedure is unique to a hydraulic system because there are no structural or reducer load limitations beyond that of the rod-string capacity. The long-stroke improves down-hole equipment runtimes by distributing the wear over a larger surface and by reducing the cyclic fatigue on the rod-string. While the hydraulically actuated sucker rod pump is not appropriate for every well, it does offer significant advantages in those wells where it is suitable. These advantages include long-stroke capability, remote optimization, and safe operation in terms of no external moving parts. The complete system is simple, cost effective, and portable, making it ideal for both permanent and trial installations.
Notes:
2013 International Sucker Rod Pumping Workshop
Technical Presentations
Session II:
Design, Automation, Optimization, Challenges
/ Session Chair:
Norm Hein
Presentation 2 Title:
Modified Everitt-Jennings Method with Iteration on Dual Damping using Fluid Load Line Computation and Multiphase Flows: More Results / Company(ies):
Weatherford
Author(s):
Victoria Pons, Ph. D. / Contact Information

Abstract:
The Modified Everitt-Jennings Algorithm with dual iteration on damping combines automatic selection of an upstroke and a down stroke damping factors along with a fluid load line computation to accurately compute the fluid load. The fluid load is the difference between the upstroke fluid load and the down stroke fluid load. Using multiphase flows, this allows for an optimum computation of the fluid level and therefore refinement of the damping factor.
The benefits of accurately computing a trusted fluid level, fluid load and pump fillage for every stroke at any given time is crucial is optimizing production and reducing cost during the pumping cycle.
In this presentation, examples from the field are studied and presented showing the robustness of this new algorithm.
Notes:
2013 International Sucker Rod Pumping Workshop
Technical Presentations
Session II:
Design, Automation, Optimization, Challenges
/ Session Chair:
Norm Hein
Presentation 3 Title:
Advantages of Rod Pump Control Systems on San Juan Basin Coal Bed Methane Gas Wells / Company(ies):
ConocoPhillips
Author(s):
Joseph R Colley
Seth Loggins / Contact Information

Abstract:
ConocoPhillips demonstrates the value of using rod pump control systems for pumping units operating in coal bed methane wells in the San Juan Basin. ConocoPhillips has been installing rod pump control systems on our coal bed methane wells for the past 3 years. ConocoPhillips presents data that validates the program failure rate reduction predictions, demonstrates a reduction in operating expense over time, and confirms that production targets can be sustained while daily runtimes can be reduced significantly. Additional benefits included reducing equipment wear, early problem detection through remote monitoring, health and safety improvements through engineering controls, and lower fuel gas consumption.
Notes:
2013 International Sucker Rod Pumping Workshop
Technical Presentations
Session II:
Design, Automation, Optimization, Challenges
/ Session Chair:
Norm Hein
Presentation 4 Title:
Restricted Intake / Company(ies):
Echometer Company
Author(s):
Jim McCoy
Lynn Rowlan / Contact Information

Abstract:
The gaseous liquid column above the TAC restricts gas flow up the casing annulus from below the TAC and causes high pressure gas to accumulate between the bottom of the TAC and the pump. This accumulation of high pressure gas causes a back pressure against the formation that restricts production from the formation.
Studies were performed on several problem wells that had the pump below the formation with a high fluid level, yet had very poor pump fillage. The tubing had a TAC about 1000-2000 feet above the pump. The casing annulus below the TAC was full ofgas with very little liquid. The casing annulus above the TAC had a high gaseous fluid level and a lot of liquid. The TAC was causing the liquid concentration below the TAC to be less than the liquid concentration above the TAC. The annular gradient changes at the TAC, from a gaseous liquid column to a high pressure gas column below the TAC.