Pushing the envelope on LWD, geosteering
Critical D&C issues with Ian Falconer, Schlumberger
By Katie Mazerov, contributing editor
Ian Falconer is marketing and technology manager for Drilling & Measurements, Schlumberger.
DC: What are some of the key drilling and completions challenges facing the industry, and how are you responding to those challenges?
Falconer: I would group our key challenges into three broad categories: exploration, managing mature assets and unconventionals.
Firstly, in exploration, the primary purpose of the well is for information, to confirm that the play is there, what the rocks and fluids are, and the size of the reservoir. As these exploration opportunities get more complicated, it becomes more difficult to capture this information and there is increasing drilling risk.
Secondly, with regards to mature fields, we have to remember that around 70% of the fields that are producing today have been producing for more than 35 years. Therefore, there is an ever-increasing challenge to maximize the performance of these assets. It’s really important for the operators to be able to squeeze the last drops out of this existing production base.
The third area involves the shift toward unconventional resources, primarily in North America. The challenge here is to develop the necessary services that will allow us to efficiently exploit these reserves. Here we are talking about drilling much higher-intensity clusters of wells, which will require more of a well manufacturing approach.
DC: Specifically, what technologies have been proven in meeting these challenges?
Falconer: In terms of exploration, our focus is on expanding our portfolio of logging-while-drilling (LWD) measurements. It’s all about trying to understand the formations better and using those measurements to minimize drilling risks. Of particular interest to the industry is our ability to now take downhole pressure readings while drilling along with our drive to eliminate downhole nuclear sources while drilling. We are the first in the industry to introduce a density measurement that doesn’t require a radioactive source.
Over the last 12 months, we have seen a significant uptake in terms of LWD seismic services. Here we are using real-time LWD seismic wave forms to actually reduce surface seismic uncertainty. This allows us to accurately pick casing points, and we now have examples of this technology being used to place wells with respect to the flank of a salt diapir.
Another key enabler in this area is the OSC operation support center. These centers focus on improving our customers’ performance and our service delivery by using rapidly developing information technology resources to make the best use of wellsite data in real time. We have a network of these OSCs worldwide, each with a core group of experts providing 24/7 support to their regional drilling operations. Here, drilling engineers and geoscientists are collocated and have real-time access to the rigs. They provide our wellsite engineers with operations support and are able to provide a more in-depth analysis of the well data such that better drilling decisions can be made.
The center in Aberdeen, for example, provides ongoing support to over 25 rigs and has even progressed to the stage of remotely controlling some of the wellsite operations. This is one of the largest real-time drilling support centers in the world today.
In terms of mature fields, we see a growing trend to more complex and longer-reach wells. A key challenge in drilling these wells is the transmission of the required data from the bit to surface. We continue to push the boundaries of mud-pulse telemetry, and last year our team helped Maersk Oil Qatar break 10 world records with an extended-reach offshore well in the Al Shaheen Field. Using a high-speed telemetry system, which can transmit measurements 10 times faster than conventional methods, we were able to transmit a full complement of real-time LWD images and drilling parameters at a total depth of 40,320 ft.
For unconventional resources, we see our key contribution as being a step change in operational efficiency and accurate well placement, as well placement precision will be much tougher than what we face today with exploiting conventional resources. Here, our efforts are focused on the continuing development of high-build-rate RSS services, new-generation surveying and ranging techniques, automation and remote operations using our OSCs. We are working closely with our Integrated Project Management segment to ensure we address the operation efficiency needs across the entire drilling process and not simply in the Drilling and Measurement domain.
DC: What are the industry trends specifically in terms of rotary steerables and geosteering?
Falconer: We continue to invest heavily in expanding our rotary steerable portfolio. We now have a range of rotary steerable tools from 3 7/8 in. to 26 in., all the way from the top of the well down to the smaller-hole TD sections.
The key challenge for this technology is to be able to steer more aggressively at higher build rates. Our clients are looking for rotary steerable capabilities at 12-15° per 100 feet and higher, to help them drill re-entry type wells and to access unconventional resources.
With regards to geosteering, Schlumberger was one of the founders of geosteering technology back in the late 1980s. When we first introduced LWD resistivity, we were doing basic geosteering by identifying formation boundaries when we crossed them and then steering back into the reservoir.
The challenge here has always been how soon do you see the boundary so that you have time to turn the well before you exit the reservoir. Since then, a lot of effort has been put into enhancing this technology to allow us to read deeper into the formation and identify bed boundaries earlier. We now have a service that was commercialized at the end of last year called the PeriScope bed boundary mapper. This gives us a much deeper reading, up to 15 feet away from the borehole, and provides our clients with much greater confidence that they can keep the well within the sweet spot of the reservoir.
DC: How has automation progressed in the drilling and completion industry in the last few years?
Falconer: The feeling in the drilling industry is that the take-up of automation has been somewhat slow. However, in the last couple of years, automation has become more commonplace, particularly for the drilling contractors, with things like automatic pipe-handling equipment and use of auto-drillers. From our perspective, the focus on automation is on the efficiency and performance side. I would say a good example of where we’ve moved forward is with our rotary steerable systems. We now have control within the tools that allows us to maintain a specific line or direction without actually having to intervene from the surface.
Another example involves the way we talk to our tools downhole by changing the mud pulse of the flow and pressures that go to the tools downhole. Historically, that has been done manually, which slowed down the drilling process. Now, we’re at the point where we have automatic pump control equipment, which improves techniques to talk to those tools downhole. We use this for controlling our downhole pressure test tools, or if we need to send a command to our rotary steerable tools. This way we’re able to eliminate drilling flat time because we’re able to automatically generate the flow changes while we’re drilling, and therefore we don’t disrupt the drilling process. With the advent of wired drill pipe, we can see further step changes.
DC: What are the new technologies the industry is still waiting for?
Falconer: The future technologies will be an extension of the direction we’re already going. The industry is looking for even better illumination of the reservoir, particularly in complex geologies and subsalts. We have a better picture using LWD seismic today, but it’s still not crystal clear. It could always be clearer. We will continue to push the envelope on that.
The same is true for rotary steerable capabilities. The technology is there now. We’ve proven the ability to get up to 15° per 100 feet build rate, but as we move forward, there will be more complex geometrical well profiles. We need to push the rotary steerable capabilities further.
On the geosteering side, again, we’ve proven that we can now provide deep readings, up to 15 feet away from the bit. But there is still the need to be able to look even further out and not just from side to side, but also to look ahead of the bit.