need advise on gas lock problem

[dukehorse]

I am trying to move 450 bpd with a tubing pump from a depth of 4100'. The problem is I have to set the pump 90' above the perfs due to a stuck tubing anchor and pump left abandoned in the well. I built the biggest gas anchor that would fit inside the casing. It is 4" with a 2" dip tube. Not quite enough by my calculations. This also acts as a centralizer leaving very little space for gas to get by, could that actually cause more gas to enter the pump? Next we are going to pull the pump again and install high compression valve cages and set the plunger as low as possible. Does anyone have field experience combatting gas lock that could possibly give me any advice? I have produced this well with the same pump setup several years ago with no trouble, the only difference is the gas anchor is bigger now. It will gas lock in less than 24 hours, where as before I would lose some efficiency but it would still produce. Thank you for any wisdom you can offer.

 

[zdas04]

Need a bit more information to be able to help. How much gas are you producing? What is the flowing tubing pressure? Is the pump discharging to a production unit or going straight to tanks/pipeline? How fast is the pump going?

David

 

[dukehorse]

This well should be able to produce 120 mcf once it is pumped down. In the past it would produce when pumping 450 bpd. It takes about 6 weeks to draw the formation fluids down to 450 to get it producing. It's got a 2 3/4 tubing pump taking a 110" stroke @8 strokes per minute. The gas anchor is 4" i.d. with 2" dip tube. At 100% efficiency that should be 775 bpd. That would give a velocity of .77 feet per second in the gas anchor which is too fast. I may have answerd my own question. I beleive it needs to be kept under .5 feet per second to allow the gas to escape. You will have to forgive my ignorance on this subject, I'm just a self taught producer trying to work my way through this and try to gain some insight from others who have designed gas anchors and have some field experience with them that I lack. I don't have my notes with me so I just ran these numbers again on the calculator. Does this sound right to you? Can you reasonably expect a gas anchor to get rid of most or all the gas in a pump?