Sucker Rod Pumping Workshop Technology in a Mature Industry September 2017 John C. Patterson Consultant Retired from ConocoPhillips (2015)
It is important to honor the past while looking forward to the future.
When did Artificial Lift start in North America? 1859 when Colonel Drake rigged up a hand pump with a 20-ft piece of pipe to his rig s walking beam. This was the first commercial oil well on artificial lift. In 2017 it is 158 years since oil well artificial lift started. Problems of Pumping Deep Wells, Lester Uren 1925
In 1927 the deepest well was at 8046 ft (2450m) and >12,000 ft (3660m) in 1951. In 1928 very few wells were produced > 5500 ft (1680m). Drilling capability developed much faster than the ability to effectively produce the wells. Issues with crooked holes and high angle wells. Same issue today we can drill wells we cannot effectively produce. Small casing Crooked holes, high dogleg above producing zones Inclined and Horizontal wells and gas slugs High temperature > 300 F
There is a significant history of artificial lift technology development and configuration of equipment. Many new technology announcements have been tried in the past. Some are new - different ideas and technology. But some old trials become new again with better material and improved methods. Technology is catching up.
Rod Pumping Technology Development and Deployment Methods Earliest form of lift Numerous improvements Improved equipment and material Rods C, D, HS, Fiberglass Pumping units API Standardization Improved understanding and design methodology Wave Equation Tubing movement 1923 First Lufkin counter balanced pumping unit Hydraulic units available in late 1920 s. 1950 s - 12 ft conventional and air balanced units, 30 ft stroke hydraulic units.
Rod Pumping Technology Development and Deployment Methods OLD TECHNOLOGY BECOMING NEW AGAIN Producing through small diameter tubing and used as the rod string in 1937. 1937 2007
Similar Historical Improvements Technology Development and Deployment Methods 1932 First hydraulic piston pump installed Provides a means for economically producing crooked holes or beyond the range of mechanical methods. Donnelly, Modern Pumping Practices, 1937 Development reasons Enhance Production Increase lift capacity versus depth Increase lift capacity versus casing size Reduce operating cost
The Goal is to maximize profit. Rule #1 We are in the business to make money technology development must improve profit by increasing production or reducing operating cost. Rule #2 - We re not in the business to eliminate all failures but fix it right the first time to eliminate REPEAT failures. Rule #3 - Strive to understand the cause of the failure and selectively target problem areas need data and information plus evaluation to understand what is happening.
Technology Development is evaluating Ideas that will improve profit.
Technology Development is evaluating Ideas on EQUIPMENT. New lift methods (Significant cost $$ and time years) WLESP w/wet connect and Geared Centrifugal Pump Complexity and Risk - high Issue High risk, high cost and long development time. Many companies eliminated technology development and switched to fast followers of technology development. Improved lift system components (low cost, time) Based on failure statistics rod pump components, etc. Complexity and Risk - low
Technology Development is developing Ideas on DATA EVALUATION. Analytical - Data Evaluation (Low cost and time) Method of understanding designs and their impact on operation (known and new) Improve existing operation (application) Create industry groups to share cost
What causes operational problems or the system to fail? Well geometry DLS, pump inclination, casing size, clearance between tubing/casing Sand 100 micron - 0.03 ft/sec (vert), 3 ft/sec (40⁰), 4.7 ft/sec (hor) Free gas pump fillage, limits pump intake pressure Scale Corrosion OPERATING CONDITIONS
test, evaluate, document and report That s why we do science. To see if our opinions can be verified in the real world, or whether we are just having fantasies Michael Crichton State of Fear
Rod Pumping Problems - Testing and Evaluations A few examples: Gas Separation lab testing with air/water Rod compression at pump slippage testing. Data Evaluation MPRL/PPRL
Gas Separation What does your gas separator intake look like? Does it make a difference? Quiet space Tested gas separators with air and water (University of Texas) Do you use a perforated nipple as the gas separator intake?
pump liquid fraction Technology in a Mature Industry Gas Separation Testing Best gas separator has smooth entrance flow to reduce gas entering but also let the gas out. The inlet configuration impacts the liquid loading and gas venting from the gas separator. 2 Perforated Nipple 24 3/8 holes 1.00 0.95 0.90 0.85 0.80 0.75 0.70 0.65 0.60 Downward liquid velocity 6 in/sec (entry below separator) Grouped by inlet slot width Perforated Nipple are they all the same? 1/8 inch 1/4 inch 3/4 inch 1 inch 2 inch 6+ inch 0.55 0.50 0 10 20 30 40 50 60 70 Superficial gas velocity annulus, ft/sec
Pump clearance and slippage Field trials Same well, SPM, SL Pump Clearances from 0.003 to 0.020 Tested with air and water (Texas Tech University) New slippage equation developed Validated in field applications Slippage 0.14 SPM 1 453 DPC L 1.52
Data Evaluation MPRL/PPRL Is a relationship to failures versus MPRL/PPRL? As the MPRL/PPRL decreases there is a point where the failure rate significantly increases. 4500-5000 0.2 8500 0.4 Need to know operating conditions included with failure data. Values can be different for each field and the desired production rate.
1.67 f/w/y 1.67 f/w/y 1.42 f/w/y 0.56 f/w/y 0.86 f/w/y 1.58 f/w/y 0.49f/w/y well count by group 0.62 f/w/y 1.72 f/w/y 0.61 f/w/y Technology in a Mature Industry Data Evaluation MPRL/PPRL 6000 to 9700 (average 8700') 500 to 800 BPD 35 50 30 45 40 25 35 20 30 <1 f/w/y 25 >1 f/w/y 15 20 #wells 10 15 5 0 <0.2 0.2 to 0.3 0.3 to 0.4 0.4 to 0.5 0.5 to 0.6 0.6 to 0.7 MPRL/PPRL 10 5 0
Rules of Thumb Caution Need to understand the basis of the Rule of Thumb development.
Develop ideas test, evaluate, document and report. Hopefully that s why you are here.
Technology in a Mature Industry September 2017 John C. Patterson
Gas Separation additional ideas Numerous gas separators and methods currently available operators should test, document and present results. Results will be different depending on the application API < 35 > Slug mitigation Develop back pressure control gas slug increase pressure then reduce surface casing and downhole. Inclined wells Test bottom feeder intakes