Extended Reach Drilling – The Offshore of Tomorrow

While there is some disagreement as to its prospects, some say that offshore drilling looks to be one of the biggest growth markets in the energy industry. In an effort to find more viable deposits, producers are turning to ultra-deep-water projects for new supplies. Goldman Sachs predicts that the offshore drilling industry will grow 40 percent annually through 2016. Some of the most promising advancements in offshore drilling have come from extended-reach horizontal drilling. While more difficult than traditional vertical drilling, recent technological advancements have helped improve horizontal drilling's accuracy and helped lower its cost.

Extended reach drilling, or ERD, of horizontal wells isn't a new idea. In the 1970s, British Petroleum's Wytch Farm project was the first to use ERD to reach deposits under Poole Bay, just off the coast of Dorset. Because the area was a popular recreation destination, traditional vertical drilling was not going to be possible. Instead, BP used a horizontal method, extending about 33,000 ft., to develop the field with minimal environmental impact. Their efforts actually won them the Queen's Award for Environmental Achievement. You don't often hear of petroleum companies winning environmental awards.

 
Credit: RWE

Extended reach drilling starts off like traditional drilling. Beginning at an on-shore site, the well is initially drilled vertically and then deviated, continuing horizontally until it reaches the deposit. This may sound much more expensive than simply building a rig in the ocean, but it can actually be cheaper. ERD requires no production islands or subsea equipment and often times requires fewer pipelines. This not only has an impact on economic considerations, it can also positively impact permitting. ERD wells can also improve productivity and increase recovery via access to otherwise inaccessible reserves.

After the 2010 Deepwater Horizon BP spill in the Gulf of Mexico, offshore drilling has almost become a dirty word(s). People don't like the idea of huge rigs invading the ocean and sucking oil from beneath the sea. But horizontal drilling can completely avoid harming or even interacting with ocean life. In fact, it never even has to come into contact with the sea at all. This could easily have a positive impact on public perception of deep-sea offshore drilling.

 The ability to bore a well over long distances can be tricky, but a new advancement, inspired by Apple's iPhone, helps make drilling more accurate and therefore more efficient. In order to adjust the screen depending on which way you're holding your phone, the iPhone uses something called a "small-scale accelerometer" that senses changes in movement around it. When applied to a drill bit, this technology creates "smart" tools that are able to sense where they are in space as they bore through the earth.

This is especially important when drilling horizontally. Deposits can be as narrow as just tens of feet thick, so accurate drilling is paramount. Control of the drill bit is the most important factor in achieving success in horizontal extended reach drilling.

ERD is in action in locations all over the globe. As of August 26, 2013 the current record holder for the longest well is the Orlan platform in the Chayvo zone with a length of 40,354 feet (or about 7.6 miles).

Extended reach technology will allow many parts of one reservoir to be accessed from one location, reducing the number of platforms needed. By using this technology, previously inaccessible resources can be developed - along with this fact and the environmental benefits, ERD seems like a good plan for the future.

The Companies Leading the Way

Exxon is at the head of the pack in ERD technology. Their "Fast Drill Process" is helping to make them an industry leader. This process uses a "physics-based method combining real-time digital analysis of the drilling system's energy consumption," along with a "structured" approach to well planning and design that "helps ensure efficient drilling." Exxon says that this technique has improved their drilling rate by 80 percent since they began using it. The Exxon subsidiary, Exxon Naftegas Limited (ENL) operates the Sakhalin-1 Project which boasts the world's longest horizontal well. Exxon says that their "fast drilling" technique is instrumental in their long distance extended-reach success.

RWE Dea, an exploration and production company, is also looking in to technologies that will make extended reach drilling easier and more efficient. Along with a partner company, RWE is "developing a new drilling method in which the fine particles of rock produced during drilling (so-called cuttings) are not removed from the borehole by traditional means (via the annulus) but through the inside of an innovative double drill string." This method will ensure that the annulus does not get blocked up and also enables "better control on the pressure and volume flows." RWE is also working on using an aluminum drill string as well as developing a carbon fiber-based plastic material that is "very strong yet lightweight." The lighter the drill string, the less friction experienced.

RWE is also part of a project started in 2011 by Reelwell called "ERD beyond 20km." RWE is joined in this project by Petrobras, Shell, Total and the Research Council of Norway. The goal of the project is to "verify the extreme ERD capability of the Reelwell Drilling Method (RDM)." RDM has the potential to "extend the envelope for ERD," because it allows flotation of the drillstring in heavyweight oil, reducing torque and drag to a minimum.

Another advancement comes not from a company, but from an academic setting. Aberdeen University in Scotland has developed a drilling technique that allows rock to be penetrated "up to ten times quicker than by conventional means." The method, called Resonance Enhanced Drilling (RED) uses a motion "similar to that of a conventional drill hammer," where the bit vibrates up and down as it rotates. The technology will be tested into 2015, at which time a commercially viable model is expected to be available.