reliability and maintenance of long stroke hydraulic ... · introduction : sucker rod surface...

2018 Sucker Rod Pumping

WorkshopCox Convention Center, Oklahoma City, OK

September 11 - 13, 2018

Reliability and Maintenance of Long

Stroke Hydraulic Pumping Units

Mohamed Ghareeb, Michael Mosavi, Dave Kennedy, Paul Tonks

Agenda

22018 Sucker Rod Pumping Workshop

Oklahoma City, OKSept. 11 - 13, 2018

▪ Introduction :

▪ Sucker rod surface pumping units

▪ Hydraulically actuated sucker rod pumping units

▪ SSi hydraulic pumping system

▪ Perceptions of hydraulically actuated pumping units

▪ Mitigating hydraulic oil leaks

▪ Maintenance

▪ Replacement parts

▪ Preventative maintenance

▪ Average repair and maintenance costs

▪ Reliability

▪ Conclusions

Introduction : Sucker Rod Surface Pumping Units

Mechanical long-Stroke Units

Beam unit

Linear vertical

mechanical Long

Stroke unit

Hydraulic Long Stroke Units

Wellhead

Mounted

Hydraulic unit

Skid Mounted

Hydraulic Unit Rod String

Subsurface Pump

Surface Pumping

unit

32018 Sucker Rod Pumping Workshop Oklahoma City, OKSept. 11 - 13, 2018

Tundra SSI Video_Med.mp4

Hydraulically Actuated Sucker Rod Pumping Units

Where applicable, they offer several significant

operational and cost benefits. Those benefits include :

• Less overall cost

• Wider operating envelope

• leveraging existing down-hole pump technology

• Less safety hazard during entire process


There are many variants and designs of hydraulically

actuated sucker rod pumping units each with

strengths and weaknesses.

*All units load tested prior to shipment with in house designed and built dedicated load tester*

The SSi Artificial Lift System

• Ultra Long Stroke - intelligent and high load

capacity Rod Lift System

• Two main components:• The pumping unit

• Power unit

• Available in Seven different models

*SSi Unit is a computer-controlled hydraulically driven long-stroke

high capacity pumping unit

SSi Hydraulic Pumping System

Perceptions of Hydraulically Actuated Units

• Hydraulically actuated sucker rod pumping units

have earned a reputation of being high maintenance

and prone to frequent failure

• Appears more complex than comparable

conventional beam units

• Oil leaking was a problem


Ssi Upgraded seal

types to reduce

leaks

Higher strength wear

rings capable of higher

side loads

Special type of

wipers to keep the

hydraulic system

cleaner

Hydraulic hoses of

higher pressure

ratings

Improved sealing tolerances for

optimum performance of the

seals

Oil containment to reduce

any oil leak to the

environment

Oil filtering system

to keep the oil

cleaner

Mitigating Hydraulic Oil Leaks

• Total cost of maintenance often much less compare to beam units

• All maintenance and repairs can be safely performed by a single

technician with only general hand tools

• Hydraulic parts are all easily replaced in the field in a short amount of

time

• A preventative maintenance program helps to address issues early

• Use of substandard replacement parts can negatively impact the reliability

and perceptions of the system as a whole

Maintenance

Replacement Parts


• Quality replacement parts in hydraulic system for long-term maintenance and

reliability

• Expected reliability of hydraulic systems is highly dependent on its components

• Due to system simplicity costs of major replacement parts are inexpensive

compared to conventional beam units

• Rubber hoses run for years without incidents – substandard hoses can cause

external leaks/premature failure

• High quality hydraulic oil suitable for field ambient temperature improves system

reliability

• Standard oil filers increases life time of unit

Preventative Maintenance


ITEM LADDER

REQUIRED TASK

INTERVAL , DAYS

90 180

1 CHECK/ADJUST ALIGNMENT x x

2 CHECK STATUS OF HYDRAULIC DRIER CARTRIDGE x REPLACE

3 CHECK STATUS OF HYDRAULIC FILTER x REPLACE

4 CHECK FOR HYDRAULIC LEAKS x x

5 TEST/SERVICE CWT OIL RECOVERY SYSTEM x x

6 CHECK FOR NITROGEN LEAKS (IF SIGNS OF LOSS) x x

7 INSPECT HYDRAULIC HOSES x x

8 INSPECT CABLE SYSTEM x x

9 CHECK ROD ROTATOR OPERATION (IF APPLICABLE) x x

10* x REPLACE AUTO LUBRICATORS x REPLACE

11 x BLEED CYLINDER (IF NEEDED) x x

12 x INSPECT PULLEY ASSEMBLY x x

13 x INSPECT POSITION SENSOR x x

14 CHECK MOTOR COUPLERS x x

15 CHECK HARDWARE INTEGRITY x

16 LUBRICATE MOTOR x

17 CHECK FOR OIL IN REAR CWT (IF APPLICABLE) X

* Scheduled replacement is 180-day intervals but should be checked every 90 days and replaced based

on an as-needed basis

Unit Size Number of Units Avg. MTC cost/year , US $ Avg. Repair Cost/year , US $

Model 250 75 1373 2464

Model 400 40 1346 2609

Model 600 6 1488 3444

Model 800 8 1674 3871


• Maintenance requirements are dependent on the duty cycle of the equipment

• Deep wells, or high volume producers expected to have a greater demand on

the surface equipment than shallow low volume wells

• Maintenance study was compiled for 4 oilfields in Canada and USA over 5

years of operation

Average Repair & Maintenance Cost

Availability

Description Life Diaphragm pressure switch, 42V N.C., 1/4" npt, range 14.5-145 psi 9.3 Years

Accumulator, 10 liter 12.1 Years

Lithium Ion Battery for SSI PLC 8 months

Des-case extreme duty breather 11 months

Vertical level switch, Buna-N & epoxy float, 316SS stem, 8.4 Years

Hydac liquid level gauge with contacts 9.7 Years

Winters Pressure Transmitter 4 Years

Mount SAE-B 2 Bolt x 5.25 5 Years

Coupling pump hub, 7/8 x 1/4 12 Years

Coupling Hub, 1-1/8 x 1/4 11.2 Years

Insert - 55D-Hytrel 8.8 Years

Mount SAE-D 2(4) bolt x 8.75 11.1 Years

Hub, 13T8/16 Stl Bush w/clamp 8.9 Years

Hub, 3-3/8 x 7/8 13 Years

Hub, DIN 5480 spline 14.5 Years

Insert-50D-Hytrel 8.6 Years

Coil 115VAC IP65 Rated 5 Years

Coil 115VAC IP65 Rated 5.9 Years

4 pin male solder 105C, 1/2-14NPSM threads 9.3 Years

5 pin male solder 105C, 1/2-14NPSM threads 5 Years

Filter Element for 40 and 60hp power unit 11 months

Winters Instruments Pressure Gauge, 0-300 psi 1/4" NPT 7.2 Years

Description Life

Wire rope, 7/16" 6x36 IWRC XIP RRL, 20400 lbs, SSI Model 250-400 + 5 years

Celesco Position Transducer 8.5 years

Celesco Chain Model 400 6.1 years

Cable Break Sensor 5.8 years

Jack Luber 5 years

SSi Power Unit Failures records

SSi Unit Failures records

• Hydraulically actuated sucker rod pumping units have undergone significant improvements

• SSi Units represent a wide range of technologies that yield unique benefits for appropriate wells

• The stroke rates of SSi Units cover a wider operational range compared to a traditional rod pump

• Adjusting stroke rates to better optimize the system for changing well conditions allows the system to operate continuously without the adverse effects of fluid pounding

• SSi unique system design eliminates virtually all downtime and urgent maintenance

• Preventative maintenance schedule has also been shown to vastly improve runtime and reliability

• SSi units preventative maintenance is not intensive - regular filter changes and a visual inspection

Conclusion


Copyright

Rights to this presentation are owned by the company(ies) and/or author(s) listed on the title page. By submitting this presentation to the Sucker Rod Pumping Workshop, they grant to the Workshop, the Artificial Lift Research and Development Council (ALRDC), and the Southwestern Petroleum Short Course (SWPSC), rights to:

▪ Display the presentation at the Workshop.

▪ Place it on the www.alrdc.com web site, with access to the site to be as directed by the Workshop Steering Committee.

▪ Place it on a CD for distribution and/or sale as directed by the Workshop Steering Committee.

Other use of this presentation is prohibited without the expressed written permission of the author(s). The owner company(ies) and/or author(s) may publish this material in other journals or magazines if they refer to the Sucker Rod Pumping Workshop where it was first presented.



Disclaimer



The following disclaimer shall be included as the last page of a Technical Presentation or Continuing Education Course. A similar disclaimer is included on the front page of the Sucker Rod Pumping Web Site.

The Artificial Lift Research and Development Council and its officers and trustees, and the Sucker Rod Pumping Steering Committee members, and their supporting organizations and companies (here-in-after referred to as the Sponsoring Organizations), and the author(s) of this Technical Presentation or Continuing Education Training Course and their company(ies), provide this presentation and/or training material at the Sucker Rod Pumping Workshop "as is" without any warranty of any kind, express or implied, as to the accuracy of the information or the products or services referred to by any presenter (in so far as such warranties may be excluded under any relevant law) and these members and their companies will not be liable for unlawful actions and any losses or damage that may result from use of any presentation as a consequence of any inaccuracies in, or any omission from, the information which therein may be contained.

The views, opinions, and conclusions expressed in these presentations and/or training materials are those of the author and not necessarily those of the Sponsoring Organizations. The author is solely responsible for the content of the materials.

The Sponsoring Organizations cannot and do not warrant the accuracy of these documents beyond the source documents, although we do make every attempt to work from authoritative sources. The Sponsoring Organizations provide these presentations and/or training materials as a service. The Sponsoring Organizations make no representations or warranties, express or implied, with respect to the presentations and/or training materials, or any part thereof, including any warrantees of title, non-infringement of copyright or patent rights of others, merchantability, or fitness or suitability for any purpose.

reliability and maintenance of long stroke hydraulic ... · introduction : sucker rod surface...

Documents