Most oil wells need to be serviced periodically by a workover rig. The length of time between these workovers varies depending on several factors, including the well’s location, downhole conditions and the specific equipment used in recovery. Suffice it to say, workovers are expensive. Lengthening the time between them can significantly lower lifting costs and improve the profitability of a well.
The Cost of a Workover
There is no “standard rate” to bring in a workover rig. Location and demand can have a significant impact on pricing. However, even a relatively simple workover operation – like changing out a rod pump with low fillage rates resulting from gas interference – routinely costs more than $6,500 per day. A more complex fishing job can cost in excess of $9,000 per day and stretch to 4 or 5 days.
Of course, those direct costs aren’t the only expense. The downtime required for a workover means production is halted. For an average well producing 30 barrels per day, that lost production can add up quickly if frequent workovers are required. Even after accounting for flush production, the net impact can total tens of thousands of dollars per year per well.
Lower Lifting Costs with Less-Frequent Workovers
A frequent culprit in the need for regular workovers is the use of a standard B2 tubing anchor catcher (TAC). Research from Echometer Company found that a standard TAC – with an outside diameter (OD) that’s nearly as large as the casing itself – often creates a “choke point” within a well. In turn, that choke point can create a pressure drop that leads to the formation of scale, iron sulfide and paraffin. When those minerals are present, plugging is often the result. Plugging occurs when sediment bridges off on top of the anchor and effectively cements it in place. No fluid can fall past the anchor and no gas can flow up.
Replacing standard B2 anchors with the Slimline® TAC from TechTAC® can mitigate many of these challenges, and by so doing, lengthen the time between workovers.
Customer Success with the Slimline
The results of switching to the Slimline will vary depending on well conditions, location and other factors. However, many customers have experienced a significant reduction in the frequency of workovers after the switch. And when workovers are less frequent, lower lifting costs are the result.
One Slimline TAC customer, a senior completion foreman with a U.S.-based oil and gas company, said, “We have one well that had to be pulled every 3 months due to scale. After installing a Slimline TAC, we didn’t need to pull it for 2 years.” Obviously, going from eight workovers every 2 years to just one is a sizable advantage.
Another customer saw similar benefits by mitigating the impact of sand. According to this petroleum engineer with a large production company operating in the Southern United States, “Sand was a frequent problem in many of our wells. It would fall on top of a standard TAC and cement the anchor in place. After switching to the Slimline, that problem all but disappeared.”
Faster Cutover When a Workover is Required
Even with its numerous advantages, like any downhole tool, the Slimline TAC may occasionally get stuck and require a workover and fishing job. But even in that unlikely event, the anchor maintains advantages over a standard B2 anchor. The Slimline’s unique design allows it to be cut over in a fraction of the time of a standard TAC, because only the slip protectors and slips need to be cut over.
Here’s how one completion foreman described it: “Some of our wells were producing a lot of sand, so the anchors were getting sanded in. Standard anchors would take several hours, and sometimes days, to cut over. The Slimline TAC is completely different. It took longer to assemble the power swivel than it did to cut over the Slimline anchor. Less than 20 minutes.”
As always, results will vary, but clearly the Slimline TAC is a different kind of anchor.
Lower Lifting Costs with the Slimline TAC
By extending the time between workovers, the Slimline TAC can lower lifting costs for production companies and operators. What could the Slimline do for your operations? Check out this comparison video and TechTAC’s ROI calculator to find out. You can also download the TechTAC Product Catalog to see the company’s full suite of tubing anchor solutions.
