Thread Damage Difficult to Assess on Drill Pipe
Project in Turkey Traced to Top Sub, Pipe Mismatch
Once, I worked with Givens International and we sold some drill pipe to a good customer in Turkey. The pipe would go on a new Driltech rig that our customer had sold for a water well application. But we got back reports of thread problems. I had to go to Turkey to check it out.
Of all pipe issues, thread damage is the most difficult to diagnose. Taking measurements of a damaged connection — if that is all you have — likely won’t help determine if was manufactured correctly. How the damage looks and where it is on the connection can give us some hints. Also, the timeframe: Did this occur on the first trip downhole, the second or after a few months?
If we can inspect other drill pipe from the drill string, we can potentially see damage that had not yet developed to the failure stage. We can use this information to develop a list of potential causes and, thereby, a list of list of culprits. Contractors like this list to include manufacturing-related problems, and manufacturers hope it is provable operator error. Distributors are stuck in the middle. In reality, many factors can trash a thread — from not using a good grade tool joint compound to rig issues. I have told tales here of silly operator mistakes, and I have tales of silly rig manufacturer errors that I have not yet told (to save their embarrassment).
The report from the field described damaged threads, some of which had galled. First, I wanted to inspect the damaged items, then see how the rig had been set up and watch it run. Since some of the 40 joints were unused, I also wanted to see if those connections gaged properly. I would need to take some tools and a thread gauge. But I needed a metal carrier to properly pack the gages and tools, to avoid damage and make them easier to carry. My wife, Randy, and I set out to find such a carrying case.
We were having no luck, until we stopped at Central Tractor. They had Porter Cable power tools in metal boxes, which looked like a good size. We would buy the tool — a saw — to get its metal case. I picked one case up from the shelf. It did not seem heavy enough, so I opened the box to find that someone has stolen the saw and left the empty box. What luck! I bought the empty box for $15. Randy cut thick foam padding and created a great case with a spot for every tool.
We packed spring calipers, dial calipers, depth mics, files and thread gages in the box, which was about 8-by-4-by-18-inches with “Porter Cable Power Tools” in big letters on the sides. Randy drove me to the airport and off I went. I flew to Frankfort then to Istanbul with my carry-on luggage and my heavy metal box. This was before 9-11 but there was still customs and these foreign airports had other security checkpoints. I was afraid to check the metal box at the ticket counter, so I just carried it on the plane and slid it mostly under the seat. No one had asked me to open it.
On the Ground in Istanbul
I landed in Istanbul and met our customer’s product manager, Ahmet, who spoke English well. As we headed out to his car, I noticed he carried a paper bag. Did he buy something at the airport? But, when we got into his car, he reached into this bag and pulled out his car radio. He stuck it back in its slot and we drove off. Evidently, thieves target car radios in Turkey. When you park your car, you take your radio with you.
We drove to his shop where I met others, including the Driltech factory rep and a factory technician. We had lunch and discussed what had happened. Evidently, they ordered 3½ Reg drill pipe but the rig came equipped with a 2⅞ IF top sub and auxiliary tooling. Not a good jump-off point for a rig startup.
The 2⅞ IF and 3½ Reg are both API rotary shoulder connections and close in size, but they have different taper, thread form and number of threads per inch. I have never tried to screw a 2⅞ IF onto a 3½ Reg on purpose, and one might think that trying to would create an immediate problem. However, these rigs have enough torque to just about convince that 2⅞ IF it could fit a 3½ Reg. But it would be ugly. Consider also that the first connection would be the top sub to the drill pipe from the carousel, done 20-plus feet in the air, out of sight.
Certainly, they noticed this. Yet damage continued despite the installation of a new, correct top sub. It was my job to figure out why these thread problems persisted.
This was my plan: If the unused drill pipe checked out, then the damage caused by the original thread mix-up was not completely weeded out. Some of the damaged joints then damaged the new 3½ Reg top sub. The factory rep kept blaming the drill pipe. I withheld comment until we could inspect the drill pipe. We headed out to do that first thing in the morning.
I stayed in a European hotel. It was very nice with an attached casino and several shops, where I bought gifts for my wife (who was tiring of airport gifts). The next morning we went to the jobsite where the rig was set up. They had a box trailer on site where the crew stayed. I went to work on the unused drill pipe.
It was tedious to clean off the tool joint compound, and run the gages and check the stand-off and stand-ins. It took a couple of hours and I found none out of spec. That said, gaging is not a prove-all. You can make a bad thread gage. Being in the field, it was the best option I had at the time. I concluded that the drill pipe was likely OK. I looked at the damaged pieces and thread damage coincided with what I would expect from cross threading. My original thinking seemed to be on target.
Breaking the News
In their trailer, the crew shared bread and homemade soup cooked on little grills. We traded American cigarettes for Turkish ones. Who knew cigarettes had become the new peace pipe?
I let the Driltech people and our customers know what I thought caused the problem. The unused drill pipe was good. It started with the wrong top sub, and that problem was never completely removed from the drill string. Pieces damaged at that time remained in the drill string, and eventually they damaged the top sub.
We were then off to the rig owner’s office in Izmir. Some of the trip was on a four-lane highway, where a herd of sheep trimmed the medial grass under the careful watch of sheep dogs. When we got off that highway, it was a country two-lane where we had a couple of stoppages due to herds of sheep on the road. We also passed a large concrete building with razor wire and no windows. A Turkish prison! Many buildings had poured concrete construction with rebar protruding from the top, as if they might add more floors later.
We arrived at our destination and had a lengthy meeting with the rig owner and some of his people, the Driltech Rep, and our customer. The Driltech rep was pushing the fault to me. If not me, then the rig operators for not stopping immediately instead of creating more damage. Our customer seemed to agree with me, but he was in the middle and it was his job to remedy the situation and make his customer happy. I did my best to make that happen.
Our customer’s customer needed new drill pipe, top subs, hammer subs, etc. The rig and drill pipe had not matched. The mix-up seemed to belong to the rig factory that tooled the rig for the wrong thread. To make the rig owner happy, I suggested that they set aside everything that was damaged and I would help with that. Then we would put on a new matching top sub and they could use the remaining drill pipe. We would haul away all the damaged items, so they would not get used again.
Now the settlement came down to us and Driltech. I think we took the brunt, in order to keep our customer happy. I am sure we all have faced these situations: take a hit to keep your customer happy and still buying from you, or figure they are already mad and cut your losses. We took path number one and I hope it paid off.
I flew home the next day. The Driltech technician and I had the same flight in the afternoon. In the morning, we went out to explore the local shops. I saw so many bakeries. At one point, a small box truck pulled up and opened the back door. Loaves of bread stacked from floor to ceiling — not wrapped or anything, just bare. Looking across the city, it had many minarets awaiting the call to prayer. I made my last stop a bookstore, and bought my wife a Stephen King book … in Turkish.
We flew back to Frankfort and had to deplane to get our flight back to Washington, D.C. On the tarmac in Frankfort, several military types with automatic weapons briefly stopped us. They were looking for someone, they said. (I hoped it was not some shady character carrying a metal box.) But they passed us by and soon we boarded the flight home. After landing, I went through customs … and never had to open this large metal box with “Porter. Cable Power Tools” on the side. No one even asked what was in it.
Businesswise, not the best of results. Although I am convinced we were not at fault, and I think our customer agreed, it cost us money. But our customer appreciated our response and help. It wasn’t a wasted trip, though. I got to see sights and eat great food, crossed the bridge from Europe to Asia a couple of times, met good people, bought things to take home, learned that a Porter Cable Power Tools box could be good cover if you’re a smuggler, and even learned never to leave your radio in your car if you park it in Istanbul.