Singles Drilling Rig

Fig. 1—National Oilwell Varco’s Rapid Rig.

National Oilwell Varco’s Rapid Rig is a “singles” land rig (Fig. 1). Developed with a 250-ton hookload capacity for shallow-to-moderate well depths, the small size and self-deploying design allow easy transport and fast on-site rig up. The rig can deploy completely with a single forklift (no cranes or gin poles). The alternating-current (AC) -powered primary systems reduce environmental effects at the wellsite. The AC-powered topdrive remains mounted in mast with the block for transport, keeping drilling line reeved in place. The rig uses a single-speed gear-driven AC drawworks with regenerative braking. The ST-80 Iron Roughneck and the stabbing guide create an automated rig floor. The PS-21 hydraulically operated power slips further eliminate manual operations at well center and operate on all drillpipe, collars, and casing sizes up to 14 in. outside diameter (OD). The drillpipe, collars, and casing are fed automatically into the central erector arm, which stands the pipe up next to floor, where it is captured and held vertically by mousehole funnels. A link-tilt system and hydraulic elevator reach out to lift the pipe above the floor. The stabbing guide captures the tail end of pipe, followed by the Iron Roughneck operation for pipe connection.

For additional information, visit www.nov.com.

Slim Infill Well

Fig. 2—Caldeus SlimWELL hanger.

The Caledus Ltd. SlimWELL technology is a well-construction technique that is based on a bottom-up design of close-clearance, flush-jointed liners. The system can be applied to full or partial well construction. Increased pipe size at total depth can deliver technical and performance advantages. Increasing wellbore size through the reservoir could enable placing a larger liner across the reservoir. As a result, there is potential to increase initial well production by increasing perforating-gun size. The liner-hanging system shown in Fig. 2 is built into the hanger wall, allowing fullbore access for the next string. The system could reduce the environmental effects of drilling the well, with significant reductions in formation cuttings, mud volumes, cement volume, and casing weight. Because cuttings volumes are reduced, the risks associated with the failure (plugging) of the cuttings-reinjection system and well are reduced. Because of the close casing/liner sizes, the possible variety of bit and casing sizes is not commonly deployed. Careful selection is required of both primary and secondary well equipment.

For additional information, e-mail info@caledus.com.

Premixed Fracturing Slurry

Fig. 3—BJ Services’ fracturing
proppants. Left to right:
bauxite, sand, LiteProp 175,
and LiteProp 125.

Typical fracturing services require the blending of frac fluids with propping agents and other chemicals while on location before and during a fracture stimulation treatment. BJ Services’ Liquid LiteProp is a premixed fracturing slurry (i.e., fracturing fluid with proppant) that can be stored. It is transported to location and pumped downhole with conventional equipment. No sand silos, conveyers, or frac blenders are required on location. The fluid viscosity and proppant concentrations stay consistent. The neutrally buoyant fluid and proppant (Fig. 3) allow the slurry to be carried further into the formation than conventional systems. Typically, during the pumping process, most proppant materials tend to sink quickly to the bottom of the fracture while being transported by fracturing fluids away from the wellbore. This proppant system has extremely low density and has the particle strength required to resist the high closure forces of hydraulic-fracturing applications. Slower settling translates into significantly longer proppant-transport distance. To maximize conductivity where proppant flowback is a challenge, the company’s FlexSand proppant-pack-enhancement additives can be used. Even in storage wells where alternating injection and production cycles create a difficult environment, the additives enhance conventional-proppant systems. The deformable particles mitigate flowback by cushioning the proppant against closure-stress forces. Indentations created in the particles help lock the proppant pack in place so that flowback is inhibited.

For additional information, visit www.bjservices.com.

Automated Directional Drilling

Fig. 4—Inteq’s TruTrak automated directional-
drilling service.

Inteq has introduced its TruTrak automated directional-drilling service, which combines the automated steering control from the company’s rotary-steerable system, integrated directional measurement-while-drilling (MWD), and its X-treme drilling-motor technology (Fig. 4). The system operates in a sliding mode with its pads engaged and bit rotation provided by the proprietary power section. Integrated, near-bit sensors measure hole inclination and azimuth and constantly transmit the data to the surface. The system’s steerable stabilizer uses three steering pads, each capable of generating up to 1.3 tons of side force, keeping the well path on target in vertical drilling and tangent modes. Whenever the system’s near-bit MWD sensors detect a deviation from the desired well path, the control subassembly’s internal hydraulics delivers steering force to the three pads to counteract any deviation tendencies and steer the well back on track—regardless of formation dip. During build and drop sections or azimuth corrections, these pads can generate turn rates of up to 3°/100 ft.

For additional information, visit www.bakerhughes.com/inteq.

Fiber-Optic Connection

Fig. 5—Greene, Tweed & Co.'s
Fiber Optic Extreme connector.

Greene, Tweed & Co. has developed a new fiber-optic connector technology, Fiber Optic Extreme (Fig. 5), expanding the company’s Seal-Connect line of connectors. These connectors withstand temperatures as high as 432°F and pressures up to 30,000 psi. The insertion loss per channel is less than 0.5 dB, and back reflection is -50 dB. These connectors transfer data at rates 10 times those of traditional copper designs. The high data-transfer rate enables real-time measurement of well performance while providing minimum data loss. The improved real-time data collection and monitoring in downhole environments eliminate unnecessary well intervention, prevent shut-ins typically necessary for pressure measurements, and optimize placement of new wells. The hermetically sealed connector fits in external housings that measure less than 1 in. OD.

For additional information, e-mail gdenardo@gtweed.com.

Chemical Cutter

AnTech Ltd. has introduced its new Chemical Cutter Firing Head, which is designed to actuate a chemical cutting tool without use of an electrical cable. The chemical cutter requires a pin to strike an explosive charge with the correct amount of energy to ignite it. The firing head achieves this energy hydraulically by building up a precise amount of differential pressure behind the firing pin to release it. Because no electrical cable is required to actuate the cutter, it can be run on small-diameter tubing or 1-in. coiled tubing (CT) for cutting deviated or horizontal wells. This tool enables chemical cutting in locations where it is impossible or impractical to run electrical cable. The tool uses an integral ball-release and fishing neck, so that if the cutting string becomes stuck, a ball can be dropped down the tubing to carry out a controlled release. The firing head has dual nonreturn valves, with no need for a separate valve subassembly, keeping its overall length to a minimum. The tool was developed originally for a North Sea operator to assist in freeing a 1 3/4-in. CT string that had become stuck in an offshore well.

For additional information, visit www.antech.co.uk.

Visualization Environment

Epsis is working with Chevron North America E&P Co. to create and evaluate a prototype visualization environment that includes the company’s Epsis Real-time Assistant software, ERA. The installation is being evaluated to assist planning of daily operations for the onshore San Ardo field in the San Joaquin Valley of California. Integrated operations optimize oil and gas production by making real-time-measured production data and the associated analysis available to engineers and operators. All personnel have continuous access to the basis for operational decisions. The software system transforms raw data from the reservoir into meaningful information delivered in real time. The company develops technology and work processes and designs collaborative methods to implement and integrate real-time technology and operation centers.

For additional information, visit www.epsis.no.