Workover Rig Best Practices
General Do’s & Don’ts.
-Op check the BOP’s BEFORE you install them on the Well.
-Always use a Night Cap on the top of the TIW valve when you leave for the day.
-Visually insect that the Rams on the BOP are closed, and back them up at night when shutting in.
-ALWAYS get a Strap & Count coming out of the hole. Account for every piece of tubing on location, whether you run it in the hole or not, that way you have a positive count. Knowing what is on location before you trip back in is the right way, the only way.
-New rings are cheap – run them.
-Nipples should have needle valves then a gauge. Don’t get into the bad habit of just putting a gauge into a threaded nipple.
When Pulling Rods
When you unseat the pump, don’t pull much more over 2#/Ft. Example: at 10,000′ don’t pull more than 20,000# over rod weight.
- On-Off Tool. (Left Hand Release) Set down about 3% from neutral weight, and put in left hand torque. When you feel the tubing torque up, hold it in, and give a couple short bumps down to transfer the torque down through the deviations. Hold the left hand torque on the tubing and come up slowly to neutral weight, or just below it. The tool should be released, if not, repeat the procedure. Once you start pulling and the tubing goes into a state of tension, the torque won’t transfer, it needs to be travelling in ‘compression’ to transfer the torque downhole.
Removing Tubing Flange/Landing BOP’s
-Kill the backside with hot fluid. The extra stretch provided by the thermal elongation of the tubing will help with the amount that you have to pull when you unseat the tubing spool/tubing flange.
Pulling a tubing anchor/(no seal)packer and replacing it….
Obviously there a thousand ways to do this, on a thousand different wells… this is just a set of quick notes on pulling and replacing tubing and a subsurface rod pump.
If you ever trip a TAC (Tubing Anchor/Catch), always replace it every time. The shear pins get weakened from setting the assembly, and then overpulling to land the tubing. Once the pins have been weakened, they can be susceptible to early breakage. Replace the seating nipple while you are there. Save time and money by doing it right the first time.
Setting Depth- Look up the stretch coefficient in the Baker Book (or other source if you have it) and compute the stretch needed to land the tubing flange.
(Set Depth in K/Ft) x (pull in K/Lbs) x (stretch coefficient)
2-7/8″ 6.5#/Ft tubing set at 10,000 FT with 20,000 pull = 10 x 20 x .22075 = 44.15″
For most situations the tubing will be in tension to keep it from buckling. Link to a great article explaining this more in depth.
When seating the Tubing Anchor/Catch, use the torque of the hydraulics of the rig to determine that the number of turns is put in. Normally the tool spins an unknown amount going down hole. Let the pressure gauge on the rig indicate when you are catching torque, it will usually increase about 300-500 Psi. Once you catch torque, pull into it a little, release, and pull into it again. Then you can go down (about 20,000# up, 20,000# down for a 7″ TAC set at 10,000′ ) to make sure it is set.
When Running Rods
-If you are working when it’s cold out, check the Torque often when tripping in rods. (about every 5 stands)… As the hydraulic fluid heats up it changes the torque at the tongs.
-Seating the pump…When in Doubt…Make sure you displace some fluid down the tubing past the Seating Nipple before you seat the pump, otherwise, debris can get into the seating nipple and prevent a good seal, or possibly prevent you from landing the pump seat. Pump some heated fluid down the tubing, and then when you have movement (put the well on a suck) seat the Rod Pump.
Temperature affects many of the variables involved in torquing up rods. The official recommendation from the API (API RECOMMENDED PRACTICE 11 BR (RP 11 BR)) Should be used as a reference. it should still be out on ‘The Internet’ – try to Google it.
-Electric Submersible Pump [ESP]
-When running a submersible pump, only use about 500 Psi closing force on the Annular Hydril, or risk smashing the lines/cable.
Have an Idea for a best practice? send it to bestpractice@wellcompletions