NEW RIG DESIGNS

Rack and pinion design enables rig to perform extended-reach laterals at shallow depths

Horizontal Well Drillers (HWD) has deployed its second-generation drilling rig this October. The rig’s unique rack-and-pinion design allows horizontal drilling at shallower depths, compared to conventional rigs. The new drill rig can be built on a trailer or heavy transport that can be moved from site to site easily. The operator sets the rig upright by activating two hydraulic cylinders that are mounted to the backside of the rig platform and to the trailer. The drilling rig’s main design feature, which greatly contributes to its horizontal capability, is its hydraulic rack and pinion system. Due to hydraulic motors that move the drillstem up and down, the rig has a push and pull rating of 500 klb. Designed for mobility, the rig can be rigged up in one day compared to two to five days with conventional rigs.

Fig. 1. Horizontal Well Drillers’ rig can be rigged-up in one day.

Benefits of the new technology include:

• Maintain extended-reach laterals down to 6,000 ft, with lateral lengths to 5,000 ft
• With maximum torque rated at 64,000 ft-lb and maximum depth rating of 15,000 ft, the rig is designed to use up to 5 in. and 65/8-in. drill pipe
• Use of one 5-in. drillstring bypasses need for multiple strings of pipe
• Mud pits are trailer mounted and self contained
• Mud pumps and service equipment are all trailer mounted
• One-day rig up and one-day rig down
• While running casing the drill can rotate and circulate the hole
• Rig is 90% self-automated
• Enclosed mud cleaning system
• One drilling rig from start to completion
• Small footprint of 200 ft x 200 ft pad.

Fig. 2. The company’s new rig will have extended reach lateral capacity up to 7,500 ft after further testing and development.

HWD tested its rig on 10 wells in Indiana. The area had existing vertical wells; the company’s new rig was drilled to the same depth as the offsets and then kicked off to horizontal from those same target depths. The very first well was drilled, from 400 ft to 700 ft with 5,000 ft laterals, and completed in 16 days. The next wells were similarly drilled out and completed in 14 days. Where it has taken three rigs in the past, this was done with one. HWD set surface pipe, intermediate casing, and cut the lateral, while maintaining a high ROP. The wells that have been drilled ranged from 400 ft to 700 ft deep with horizontal ranges from 4,000 ft to 5,400 ft in less time established with the AFE and have increased the pay zone exposure by as much as 108 times.