Despite the downturn in oil prices, many companies are still finding success by increasing efficiencies and decreasing operating costs, often through the use of innovative new technologies or the re-purposing of existing ones.
What are the challenges of artificial lift with horizontal wells?
Basically, all of the artificial lift systems were designed, and have historically been run, in the vertical part of a wellbore. In recent years, with the explosion of horizontal drilling, we’ve been trying to position these pumps that were designed for vertical conditions around the bend and into the horizontal well, so they’re now lying on their side. As a result they’ve become highly inefficient and highly unreliable – meaning they fail a lot.
What is unique about the HEAL System™? Why is it so innovative?
The main reliability problem with artificial lift systems is to do with the fact that pumps have moving parts. And these moving parts don’t like being on their side. As a result they break down frequently and they cannot lift as efficiently as they should.
The whole premise of the HEAL System™ is to allow that pump to remain in the vertical. What we do is we allow the pump to be positioned in the vertical, where it’s happy, and the HEAL System’s™ job is to get the fluids from the horizontal, up around the bend, up into the vertical, and then give the fluids to the pump.
The patent pending HEAL System™ is placed downhole below traditional artificial lift in a horizontal well and is comprised of a seal, a sized regulating string, and a HEAL Vortex Separator.
The patent pending HEAL System™ is placed downhole below traditional artificial lift in a horizontal well and is comprised of a seal, a sized regulating string, and a HEAL Vortex Separator.
In other words we’ve figured out the way to do two things: to get the pump out of the horizontal and into the vertical and to get fluids from the horizontal into the vertical – and we’re doing it with no moving parts.
Now, what is really important to understand is that in order to maximise production, the pump needs to be placed at the lowest point in the well. That way we can maximise the pressure difference between the reservoir and the wellbore. The larger that difference is, the greater the flow coming into the wellbore.
In the past, the only way to achieve that was to force these pumps right into the horizontal part of the well.
With the HEAL System™ we have discovered that we could lift fluids – gas and liquids – from the horizontal and into the vertical by conditioning the flow. We have achieved that by reducing the cross-sectional flow area around the bend between the horizontal and the vertical part of the well.
What we have discovered is that when you make the flow area smaller, you have gas and oil flowing at a higher velocity. When you do that the flow regime changes the density of the flow . Think of it as a change from liquid to mist. .
How we did that was with special plastic linings. All wells have jointed tubulars, each of them about nine metres long, that are threaded together and run from top to bottom. In some of those joints – say 30 of them at the bottom, for 300 metres or so – we have this internal plastic lining put into them to create this desirable flow condition that we want to give us a lift.
We can vary the thickness of the plastic lining in response to the varying conditions in the wells. All wells have different producing conditions, so we have to adjust the well, using the incredible versatility the plastic gives us, to the different conditions.
facilitating problem of messy flow
When we are doing our lift stage, there are two things that we are looking for. One of them – which I have already mentioned – is creating the condition of a very low density fluid to mimic that low-pressure condition at the bottom of the well that maximises production. The other – and this was our big discovery that led us down the path of developing the HEAL System™, was that it also solved the problem of messy flow.
Artificial lift systems struggle to handle rapidly fluctuating fluid rates and surges, solids issues and gas interference – all common in horizontal wells, that can result in:
Excessive downtime
Excessive workover costs
Inadequate drawdown
These big, long horizontals that go for a couple of kilometres, are actually very good natural separators of fluids. What happens, though, as a result of that is the flow that comes out of the horizontal wellbore, to where the pump is normally placed, naturally becomes unstable, inconsistent, and messy. And it is specifically a feature of horizontal wells.
Horizontal wells are challenged by issues associated with inconsistent, messy flow.
What you have to understand is that with horizontal wells, the flow coming out may be straight gas for 10 minutes and then for the next 10 minutes it might be straight liquid. And for the next 10 minutes there might be nothing. The problem is that no pump likes messy flow.
What happened with the HEAL System™ is that as we studied the flow coming out of the horizontal, we have found that by narrowing the pipe around the bend, we create the unique benefit of smoothing the flow out so that the well no longer produces this messy flow.
THE WAY WE SOLVE IT
Production Plus discovered the key to making artificial lift in horizontal wells less painful is to smooth flow.
We developed the HEAL System to complement existing artificial lift systems, settling the messiness of horizontal flow, reducing fluid density and lifting fluids up to the vertical where a pump can operate reliably. The System controls solids and gas interference to protect your pump.
The System benefits a well during any phase of its life cycle.
Maximizes runtime to lower operating costs
THE HEAL SYSTEM REDUCES ARTIFICIAL LIFT COSTS
With The HEAL System, you are able to use proven artificial lift systems that are lower cost to maintain and that operators know how to manage.
The HEAL System permits installation of smaller sized pump jacks, rod strings and pumps.
The HEAL System helps you avoid costly work-overs to repair downhole pumping equipment damaged by solids and gas interference.
The System is designed to last the life of the well – allowing you to avoid intermediate artificial lifting requirements – and eliminating future major work-over costs.
Maximizes drawdown
THE HEAL SYSTEM INCREASES PRODUCTION VOLUME
The HEAL System maximizes runtime by controlling solids and gas interference.
The System operates at very low bottom-hole producing pressures to maximize drawdown and increase well production and reserves recovery.
Placement of the artificial lift system in the vertical section allows for greater pumping capacity from your existing equipment.
The HEAL System is a highly reliable system with no moving parts; it is able to manage a wide range of variable flow.
石油圈
