Wells in the Marcellus Shale include a vertical section and then quickly build to the lateral horizontal section. In many cases, the lateral truly is horizontal. After drilling a record lateral well section in northwestern West Virginia, an operator was unable to run the 5 ½-in. casing to total depth (TD). Despite three separate attempts to open and condition the hole and to run conventional casing, the casing string was unable to pass the heel of the well bore just before the lateral begins.

While the final conventional casing run was made, the operator called in Tesco to mobilize its top drive, casing running, wireless torque sub (TesTork) and casing drilling services to get the casing to bottom. Tesco set a casing running record for the 5 ½-in. lateral of the operator’s first well in the Marcellus, and then went on to break that record in a second horizontal well.

Record-setting casing run
Engineering analysis showed that the long thread connections on location were not capable of handling the required torque of 12,000 ft-lbs at TD to rotate the casing to bottom. A string of buttress thread connection pipe was dressed with Tesco’s Multi-Lobe Torque Rings and 7-in. Hard Faced Hydro-Form Centralizers and delivered to the wellsite. A Tesco 250 HMI 475 (250 ton, 475 hp) top drive was installed in the derrick with the company’s Casing Drive System (CDS).

Tesco Casing Drive System

The Tesco Casing Drive System (CDS) 250 HMI 475 (250 ton, 475 hp) top drive can typically be installed with little or no modification to any existing drilling equipment. (Image courtesy of Tesco)

The company also provided its laydown services for safely and quickly delivering each joint of casing to the rig floor. The company’s Wireless Torque/Turn Monitoring System (TesTork) was installed between the top drive and the CDS to provide real-time torque vs. turn data while making up each joint of casing to 12,000 ft-lbs.

The CDS was used to ream the casing to TD beginning at 8,700 ft (2,652 m) until TD at 13,673 ft (4,168 m). Reaming parameters of 50 rpm, 360 gpm and up to 11,000 ft-lbs of torque were required to reach TD. This well set a record for the longest cased lateral in the Marcellus Shale. However, the record wasn’t destined to remain long as Tesco bested its own performance on a subsequent well, also in the Marcellus Shale in Harrison County, West Virginia.

Back-to-back records
Following the record-setting first well, a second well was drilled to TD of 16,670 ft (5,081 m) with about a 9,400 ft (2,865 m) horizontal section to maximize the length of the production lateral and increase per well production. Rather than make what could have been failed attempts at running the 5 ½-in. casing conventionally as was the case in the first well described above, the operator again asked Tesco to mobilize its equipment to get casing to the bottom.

Tesco equipment used on this record-setting job included the 5 ½-in. Hard Faced Hydro-Form Centralizers, Warthog reaming shoe, 250 HMI top drive, CDS and the TesTork Wireless Torque/Turn Monitoring system. Each piece of equipment used in this record casing running job worked in conjunction with all of the other equipment to result in a successful project that would not have been possible with conventional casing running techniques.

Centralizers are used in the casing string to create a standoff which will facilitate improved cementing and protect the casing from wear and tear. The company’s unique design and attachment method provides superior strength and rigidity capable of withstanding dynamic downhole loads while maintaining standoff under large side forces without crushing. The company’s Radial Tubular Forming crimping process provided a strong and durable mechanical attachment capable of withstanding high torque.

The Warthog Casing Running and Reaming Tool was made up to the bottom of the shoe joint to help get the casing to TD. The Warthog design combines hydraulic and mechanical energy to break through challenging hole conditions such as bridges, ledges, doglegs, sloughing formations and deviated holes. A nose cone profile cleans and circulates while three spiral helix external blades help condition the hole and provide centralization for cementing. Hardfacing of the nose and stabilizers is standard for use in aggressive and lengthy reaming requirements. The MLT shouldered API buttress connection provides ample torque capacity for reaming.

The Warthog is ideally suited to be used with Tesco’s CDS, which allows a casing string to be simultaneously rotated, circulated and reciprocated. Developed initially for casing drilling operations, the CDS delivers all of the advantages of top drive drilling to casing running operations. The CDS replaces power tongs, traveling elevators and bails. It can be installed on virtually any manufacturer’s top drive drilling system. In other cases, Tesco can install one of its top drives on the rig for use with the CDS. The CDS can typically be installed with little or no modification to any existing drilling equipment.

Warthog, hole, Tesco

The Warthog Casing Running and Reaming Tool combines hydraulic and mechanical energy to break through challenging hole conditions such as bridges, ledges, doglegs, sloughing formations and deviated holes. A nose cone profile cleans and circulates while three spiral helix external blades help condition the hole and provide centralization for cementing.

The company’s versatile 250 HMI 475 top drive system was installed in the rig’s derrick. This particular model is rated for 250 ton casing loads and 475 hp and can be equipped with an independent diesel, AC or DC traction motor. The complete system, including the top drive, torque system and power unit, can be installed in less than one day.

Tesco’s computerized Wireless Torque/Turn Monitoring System can be used with the company’s CDS and a top drive drilling system from any manufacturer. TesTork combines state-of-the-art wireless connectivity for accurate monitoring of torques and turns when making up connections with a top drive system using the CDS. The system is independent of any top drive signals. RPM and turns are recorded from an independent sub installed on the CDS while it monitors torque measurement from 0 to 50,000 ft-lbs. It is ideal for monitoring torque during reaming operations. Display options include torque vs. turns and torque vs. time.

Premium connection monitoring includes automatic detection and marking of torque shoulders as well as delta torque. Alarms occur when make-up criteria are not met. Connections not passing specified criteria (torque, turns or time) require a forced pass by the operator with a recorded explanation for the pass.

The services provided for the record-setting lateral length of the second well was considered a Level 1 well, according to Tesco’s nomenclature. This level begins with a pre-drilled hole and then using CDS to get casing to bottom by rotating the casing and reaming. The operator’s objective was to set the 5 ½-in. casing in the 9,400 ft (2,865 m) horizontal lateral section.

Engineering analysis showed that rotating the casing to bottom would require a premium or semi-premium connection to handle torque of 12,000 ft-lbs at TD. A string of P-110 pipe with GBCDE connection was dressed with Tesco’s 5 ½-in. Hard Faced Hydro-Form Centralizers and delivered to location with a Warthog reaming shoe made up to the bottom of the shoe joint. A Tesco 250 HMI 475 top drive was installed in the derrick along with a CDS. A TesTork system sub was installed between the top drive and the CDS to provide real-time torque vs. turn data while making up each casing joint to 12,000 ft-lbs.

The well plan called for a vertical hole to approximately 6,415 ft (1,955 m) and then to begin building the curve to eventually reach a 90? lateral. Build rates reached up to 12?/100 ft (30 m). At around 7,300 ft (2,225 m) the inclination was 90? and remained within 2 to 3? of horizontal throughout the lateral section to TD at 16,670 ft (5,081 m).

The CDS was used to ream the casing to TD starting at approximately 7,300 ft (2,225 m) with reaming parameters of 5,000 to 15,000 lbs weight on bit, 30 rpm and 420 gpm and up to 12,000 ft-lbs of torque required to reach TD.

These record-setting casing runs were made possible with the application of various tools and equipment that complement each other when brought together into a seamless operating system.