Drill four wells expected to experience high mud loss with WBM
Previously in the Eagleville field, an operator drilled 8.-in lateral
sections of up to 12,800 ft [3,900 m] using OBM without technical wellbore
issues. However, the formations were prone to severe lost circulation, making
OBM uneconomical in these intervals. These very extended laterals required a
highly lubricious drilling fluid to minimize torque and drag while maximizing
ROP. The customer wanted to drill four wells with a WBM that could mimic these
properties and be a cost-efficient alternative. But using a conventional WBM
would include challenges such as a higher surface torque and drag, a lower ROP,
and tights spots caused by wellbore swelling and high friction when running
casing or tripping out of the hole.
Replace current OBM with a high-performance water-based drilling fluid
M-I SWACO, a Schlumberger company, suggested using the HydraGlyde system
to replace the current OBM system. The HydraGlyde system is a unique shale-play
drilling fluid system that competes with OBM in terms of penetration rates and
wellbore stability—while helping operators minimize environmental impact
and cost due to formation mud losses.
It was engineered with a low-solids formulation, consisting of 10
lbm/galUS [1,198 kg/m3] sodium chloride brine as the base fluid. To manage the
reactivity of the Midway shale formation, 1–2% by volume of HydraHib
shale inhibitor and 1 lbm/bbl [2.8 kg/m3] of HydraCap encapsulating additive
were added to manage the reactivity of the Midway shale formation. In addition,
up to 3% by volume of HydraSpeed ROP-enhancing primary lubricant was used to
provide the HydraGlyde system with similar lubricious characteristics to an
Reduces cost due to formation losses by USD 300,000
By using the HydraGlyde system, the operator was able to save USD
300,000 per pad in costs due to mud losses, based on the unit cost of
HydraGlyde system versus the previous OBM.
Additionally, the system enabled the bit to average an ROP of 86 ft/h
[26 m/h] across three of the wells, with the exception showing the lowest ROP
at 65 ft/h [19.8 m/h] due to severe losses encountered while drilling.