USR Drilling Technology
Most horizontal wells are drilled with conventional mud motor drilling systems. These mud motor systems are well-suited for drilling medium and long radius curves, but short radius and USR curves (particularly those with less than a 60’ radius of curvature) are more difficult and risky. USR Group specializes in drilling horizontal wells with radii of 27-60 feet using a combination of rotary steerable and mud motor assemblies which are specially designed to achieve high build up rates approaching 230° per 100’. Both USR Group’s drilling systems are specially designed to be operated from a workover type rig with pipe rotation provided by a top drive or power swivel. The use of less costly surface components and smaller location footprint translates to lower drilling costs.
What Is Ultra Short Radius?
By definition USR well specifications are:
- A Curve section with a Build Up Rate (BUR) of between 100° and 250° per 100 ft or,
- A Radius of Curvature (ROC) between 27 and 60 ft.
Beginning in the late 1980s, USR Drilling Group began development and testing of the initial prototype tools at AMOCO Drilling Research Center. These early prototypes helped cultivate the directional drilling methods utilized by us today.
Initially, all USR wells were drilled with Rotary Steerable Drilling Assemblies. However, over the past 15 years, we have developed a proprietary fleet of specifically designed Mud Motors. Today, we combine mud motor technology with rotary steerable to offer the industry a unique alternative to conventional horizontal drilling systems.
Attributes of the USR Drilling Technology include:
- Ability to re-enter existing wells completed with 4-1/2” OD casing (or larger)
- Drill a consistent radius of curvature as small as 27 feet
- Drill laterals ranging from 100’ to 1,500’
- Multiple laterals can be drilled from a single well-bore
- Compatible with any drilling medium including air, mist and foam
- Can be drilled with a drilling rig or service rig
A key benefit of USR Group’s technology is that inclination and azimuth readings are obtained only 2’ to 7’ from the bit. This reduced projection to the bit distance allows for a planar curve and smoother lateral section. Thin pay zones can be more accurately drilled with less wellpath tortuosity, providing a definite advantage for well completion and production.
USR is the preferred choice for a variety of applications.
Applications
1. Sidetracks from Vertical Wells with Water Coning
2. Sidetracks from Vertical Wells in Tightly Spaced Fields
3. Exploitation of Attic Oil From Vertical or Horizontal Wells
4. Sidetracks into Channel Sands with Surrounding Shale
USR offers the following advantages over conventional horizontal drilling systems:
- Problem zones such as water sands, gas caps and problematic shales can be avoided
- Allows a more efficient development of closely spaced fields
- Downhole pumps can be placed at the top of the formation to maximize productivity
- Utilizes workover type rigs, smaller pumps and circulating systems
- Landing in thin targets can be more easily achieved when exiting from an existing wellbore and at or near the top of the target formation