Comparative wear and friction testing of centralizers in Norway
There has been extensive combined testing of centralizer wear capabilities and friction measurement conducted in Norway by operators, in conjunction with a world renowned independent research institute. The results of this testing have been known for some time, however they are not widely distributed. In this case study we look at the data and summarize the testing results. We hope it makes for interesting reading.
A test apparatus was designed and constructed which would allow a 4-1/2in tubing with centralizers installed upon it to be run inside of a 7in tubing. The 4-1/2in tubing could then be rotated and reciprocated while measuring both sliding and rotational friction with the use of an array of sensors installed on the test fixtures. The testing was conducted with the centralizers submerged in a water based fluid.
Testing was conducted in order to measure the centralizers' wear over a travelling distance of 15km. The friction factors for sliding with and without rotation were also recorded for each centralizer type. A total of 36 tests were recorded on each centralizer type and the average results reported in the graphs below.
Several centralizer types were tested from a variety of manufacturers. We have kept the other manufacturers' names anonymous in this case study and have only described the centralizer type.
Centralizer A - Steel laser cut bow spring
Centralizer B - Steel solid body
Centralizer C - Bladerunner™ Zinc Alloy / Teflon solid body
Centralizer D - Spir-o-lizer™ Zinc Alloy solid body
Centralizer E - Composite/Plastic solid body
Centralizer F - Aluminum solid body
Centralizer G - Composite/Plastic solid body
Centralizer H - Composite solid body
Results - Friction
The ‘Bladerunner™ LT’ placed 1st for all rotational tests
The ‘Spir-o-lizer™’ placed 1st for all ‘sliding with no rotation’ tests
The ‘Spir-o-lizer™’ placed joint 2nd for ‘sliding with rotation’ tests
Bladerunner LT shown after 15km wear test run
Results - Wear
The ‘Spir-o-lizer™’ and ‘Bladerunner™’ placed 3rd in the wear testing, losing only 1mm of standoff after a 15km wear run.
Only the high friction steel centralizers had better wear resistance than these units.
The composite and polymer centralizer types suffered from extreme wear and in one case the test had to be stopped when the unit disintegrated.
The Bladerunner™ LT centralizer is the ultimate friction reducing centralizer for extended reach liners and applications where rotation is required.
Wear resistance is an important factor in the correct selection of centralizers. Operators do not have to compromise on wear resistance in order to achieve friction reduction.
Accurate torque and drag modelling should be conducted for each liner and casing running operation to ensure that the correct centralizers are selected for the application.
Marwell are specialists in wellbore construction and completion. Born from the understanding that each well and each formation presents its own unique challenges, we have set out to develop and apply new and exciting technologies for ever-more challenging applications.
To do this, we have partnered with industry-leading companies from across the globe to offer tailored solutions that are not available elsewhere on the market. Combining proven tools with our engineering approach we apply well-first thinking.
Our partners Varel Energy Solutions are widely recognized for their products ingenuity, performance and reliability. Their Bladerunner™ and Spirolizer™ centralizers are renowned for having ultra low friction characteristics and high strength construction.
The Ultimate Friction Reduction centralizer reducing both Torque & Drag with patented ultra-low friction buttons and sleeve. Demonstrated and verified friction factors of 0.12 in cased hole and 0.20 in open hole.
Utilized extensively around the world and renowned for several world record ERD wells.
Robust, cast zinc alloy construction.
Demonstrated and verified friction factors of 0.15 in cased hole and 0.20 in open hole.
To learn more about correct selection of centralizers and their impact on your well then please contact your Marwell representative or visit www.marwell-tech.no