History of the first Kaliper (ILI) tool

By: Larry D. Payne, LP Services, LLC

In July 1969, T.D. Williamson, Inc. (TDW) was visited by the General Manager of Lakehead Pipeline Company. This was a Canadian based company that operated a 34” crude oil line coming out of Canada, running through Northern Minnesota, through Wisconsin, to a refinery in Northern Illinois. He met with Burt VerNooy and Larry Payne. Prior to this meeting Burt asked Larry to cut a 36” spherical pig in half, which was not easy. This was to be used to demonstrate a flexible cup that later was to be used on the first ILI tool. In this meeting, the General Manager explained that they were concerned this pipeline contained a significant flaw in the form of dent or buckle in the section running through Wisconsin. The reason for thinking this was that the cleaning pigs were being received in a damaged condition.

At this time, Burt VerNooy was the “Director of Research” and Larry Payne was “Research Designer”. Also, at that time Burt had over 50 patents, Larry had only been employed by TDW for 5 months and coming from the aerospace industry could not spell pig and had no patents. TDW was offered $25,000 to develop a tool that would find, size, and locate this flaw. They accepted the challenge and Burt and Larry’s first thoughts were that the tool must be flexible enough to traverse a major restriction in the pipeline. They also thought that when traversing this restriction, the tool would experience a drive pressure increase. Therefore, their first design was for a tool that would traverse a 30% reduction and record a pressure increase on an off the shelf chart recorder. Knowing the flow rate and the chart advancement speed, they thought they could locate the restriction. They designed an instrument that held 63 feet of pressure sensitive paper chart and a piston that would push a stylus across the paper making a mark on the chart that was moving 4” of chart per hour. The pig in this crude oil was moving at approximately 3 mph. That would have been about 4000’ of pipeline per inch of chart. Burt mostly designed the tool and Larry made the production drawings per his sketches, had the pieces built and assembled the tool. Larry then headed to Minnesota to test run this prototype in a test section running to Superior, Wisconsin. The tool came in at pump station in Superior and looked OK, Larry opened the instrument, removed the chart that was full of vertical recordings, indicating he was getting pressure increases throughout the pig run and the battery life was gone. When he received the flow rates to determine location of any recording, he found the flow rates changed continuously throughout the run. Based on this information, he would have been lucky to locate a reduction within five miles!

Then appeared a new hire, Bob Kendall. He looked at what they were doing and recommended they use an Odometer roller equipped with magnets to trip a reed switch that would send a signal to a stepper motor that would make to paper chart proportional to the pipeline length. Larry designed the mechanisms and an odometer wheel that was near exactly 2’ circumference. One magnet installed in a wheel, positioned to trip a reed switch would give a pulse every two feet. That produced 2000 pulses per inch of chart which equated to 2000’ of pipeline per inch of chart. If they put two magnets in odometer wheel, the chart scale would be 1000’ of pipeline per inch and so on. Since the instrument would only hold 63’ of chart, the pig run distance determined the chart scale.

They added all the distance recording mechanisms, increased the spring pressure to reduce the vertical line movement, and off to Clearbrook Larry went. They also added a spring-loaded cam roller that would make noises so the pig could be more easily tracked. Larry tracked the pig over 200 miles and pulled the pig out at Superior again. This time he had a good chart length chart for distance, fewer vertical random restriction indications, but this told him nothing as to what may have caused them.

Back to Tulsa and back to the drawing board. They felt they had the distance location method figured out, but the sizing of restriction design needed to be fixed. Burt and Larry started designing a mechanical finger mechanism that would record the downward movements of multiple fingers installed inside the rear cup. So now they were measuring distance traveled with odometer rollers advancing the chart at a certain scale proportional to the pipeline length, and sizing the reduction based on the mechanical movement of fingers located inside the rear cup.

So off to Superior, Wisconsin for another run. The tool recorded a full-length chart showing a 4” plus reduction about halfway down the pipeline. Larry started the analysis by comparing known things recorded on the chart (pipe wall changes, valves, bends, etc) to the pipeline strip map distances to determine the actual chart length scale within a given area. He recalled locating the reduction from a valve about five miles away. He notified the customer of what he found and the following week met them at the dig site. It was in the middle of a field covered with about two feet of snow. There was no reason to have a 4” reduction in middle of a field. They start digging with a Trackhoe. The tolerance was plus or minus 50 feet. They dug up, exposed, about 50’ to the south and nothing, they then started digging 50’ to the north, Larry was feverously going through his location calculation again when he heard the Trackhoe hit something. As he walked up to the dig site, he heard the Dig Forman say, “They found it". The pipe was resting on a rock ledge and when the pipe was back filled with dirt and loaded with crude oil, the pipe had buckled causing a 4” reduction. Larry called the office with excitement to report the success. That occurred in December 1969, about 6 months from when they started this project.