Given the economic and environmental constraints of North American shale plays, oil-base drilling fluids are not always the optimal choice.
The exceptional drillability of non-aqueous muds in high-angle, long-reach horizontal land wells is offset by tremendously high logistical and waste-management costs that can account for half the total drilling fluids bill.
While highly inhibitive high-performance water-base drilling fluids mitigate many environmental issues, their price is often prohibitive for use in these cost-competitive plays.
Most premier water-base mud formulations lack the engineering flexibility to address the unique drilling conditions of widely diverse onshore shale plays, which demand more than a one-size-fits-all fluid system.
Recognizing that no two shale plays are alike as well as the need to rein in costs, M-I SWACO developed the HydraGlyde high-performance water-base drilling fluid system specifically for the economically challenging North American onshore unconventional sector.
The system provides a fast, trouble-free, flexible drilling fluid solution that fits within rigid AFE and HSE constraints. Its novel cost-effective chemistry reduces torque and drag in addition to shale swelling and dispersion. The HydraGlyde system delivers oil mud–comparable ROP, exceptional hole cleaning, and wellbore stability in high-angle-build and long-lateral sections—all while reducing restrictive costs and decreasing environmental impact.
Unique engineering for speed, stability, and simplicity
Conventional high-performance water-base drilling fluids provide excellent inhibition, which is the most advantageous performance characteristic of the invert emulsion muds they were meant to replace. However, typical land shale formations are more mature, microfractured, and highly laminated, making them easily destabilized by drilling fluid or filtrate. And with differences among every shale play and overburden across North America, drilling fluids must be tailored to meet specific geological characteristics, drilling conditions, and operator objectives.
M-I SWACO developed the HydraGlyde system to meet inhibition requirements while reducing torque and drag and improving ROP in the build and horizontal sections. This cost-effective chemical package provides a high degree of lubricity and also overcomes the typical drilling-related problems encountered in more mature onshore shales—gumbo accretion in the surface hole, wellbore instability, mud losses in the intermediate section, solids buildup, and hole cleaning in the horizontal section.
In addition to its exceptional drilling performance, the HydraGlyde system also generates a thin, tight, and slick filtercake that helps simplify running casing and installing the completion system.
To deliver this combination of performance and flexibility, the HydraGlyde system is engineered with three components:
1.HydraSpeed ROP-enhancing primary lubricant, which demonstrates a coefficient of friction factor of 30.8 compared with 38.9 for a higher-cost lubricant. Its unique nonhydrocarbon chemistry provides the optimal combination of lubricity, wellbore stabilization, and filtercake enhancement.
2.HydraHib shale inhibitor, an amine-based additive that provides a high degree of wellbore stability and flexibility with the ability to adjust its concentration.
3.HydraCap encapsulating additive, which replaces the conventional partially hydrolyzed polyacrylamide (PHPA) additive to minimize clay dispersion and enhance wellbore integrity. Compared with PHPA, the HydraCap additive disperses more in water and generates less viscosity.
To enhance hole cleaning and help eliminate sweeps, the HydraGlyde system also incorporates the supplemental DUO-VIS biopolymer additive to increase low-shear viscosity for cuttings transport and suspension, while the POLYPAC UL ultralow-viscosity polyanionic cellulose controls fluid loss with a negligible increase in viscosity.
Features
1.High-lubricity water-base mud system；
2.Cost-efficient chemistries；
3.Stable rheological profile；
4.Shale inhibition；
5.Low coefficient of friction factors for laterals；
6.Stable, low-shear viscosity；
7.Thin, high-quality filtercake, low fluid loss；
8. Design flexibility；
9.Minimal products required；
10.Compatible with a variety of makeup water and brines.
Benefits
1.Delivers high drilling rates in build and lateral sections；
2.Stabilizes shale sections while drilling；
3.Lowers torque and drag while drilling and running pipe；
4.Promotes trouble-free running of casing and completion equipment；
5.Provides excellent hole cleaning without sweeps；
6.Reduces dilution rates；
7.Decreases risk of differential sticking；
8.Minimizes nonproductive time (NPT)；
9.Saves drilling costs；
10. Elevates environmental profile.
HydraGlyde Drilling Fluid System Improves ROP 16% by Reducing Torque in Challenging Wolfcamp Shale
CHALLENGE
Overcome limitations in drilling torque and improve penetration rates while drilling the interbedded Wolfcamp Formation using a water-base mud (WBM).
SOLUTION
Use HydraGlyde high-performance waterbase drilling fluid system to reduce torque and achieve ROP comparable to those delivered using an oil-base mud (OBM).
Limitations on drilling torque and penetration rates in interbedded formation
The Wolfcamp Formation in the Midland basin of West Texas contains interbedded shale and limestone that can limit drilling torque and penetration rates. The curve build section through the Spraberry Formation also presented a challenge because it required higher shale inhibition compared with the lateral.
An operator in the region needed to minimize drilling torque in a 15,285-ft- [4,659-m-] MD well while drilling the curve and 6,235-ft [1,900-m] lateral throughout the 8½-in production interval. In previous wells, an inhibitive WBM was employed, but the WBM system’s torque limits impaired the rig’s overall ability to drill as fast as was possible using an OBM.
Performance comparable to an oil-base system
M-I SWACO recommended the HydraGlyde high-performance water-base drilling fluid system to reduce torque, drag, shale swelling, and dispersion while delivering exceptional inhibition. The HydraGlyde system delivers drillability comparable to an OBM while maintaining the characteristics of an WBM. The system also delivers a high-quality filtercake and a low-tortuosity wellbore that minimizes the risks of differential sticking.
The HydraGlyde system included approximately 1.5 lbm/bbl [5.71 g/L] of HydraCap* encapsulating additive to minimize clay dispersion and to enhance wellbore integrity, 1%–2% of HydraHib* shale inhibitor to provide an amine-base additive for wellbore stability, and 2%–3% of HydraSpeed* ROP enhancing primary lubricant to deliver exceptional lubricity.
The HydraGlyde system achieved an ROP increase of 16% due to 18% less torque compared with the inhibitive WBM used in offset wells.
Accelerated drilling with substantial torque reduction
The 8½-in production interval was drilled in 3.5 days, making it one of the operator’s fastest-drilled wells in the area. Drilling torque was up to 5,000 ft.lbf less than the torque required in offset wells. The entire section was drilled to TD with one bit and exhibited a smooth wellbore that was successfully cased and cemented. The customer is using these improved drilling parameters to establish higher drilling fluid standards for future wells in the area.
RESULTS
1.Drilled 8½-in production interval in 3.5 days and increased ROP 16% compared with previous inhibitive WBM applications.
2.Reduced torque by 18% compared with offset wells drilled using inhibitive WBM.
3.Set higher drilling fluid standards for future wells.
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