High temperature, high pressure (HTHP) usually imposes the most severe restraints and critical requirements within the oilfield. The accepted industry definition of an HTHP well is one that has an undisturbed bottomhole temperature greater than 300°F(150°C) and either has a pore-pressure gradient in excess of 0.8 psi/ft (0.18 atm/m) or requires the use of well-control equipment at more than 10,000 psi (680 atm) working pressure. Developing HTHP reservoirs requires highly competent understanding of the well conditions and the management of complex well control operations.
The interaction of reservoir fluids, formations, and drilling fluids in the HTHP environment requires challenging fluid formulations and the laboratory capability to perform adequate test to prepare for the well site conditions. An HTHP operation requires a number of competencies including:
- Well control situations
- Product interactions
- Drilling fluid selection
- Well and fluid behavior at HTHP conditions
- Testing protocols, both in the laboratory and in the field
- Engineering software
Regardless of the fluid type, providing the optimal system is paramount. A holistic, field focused approach identifies the fluid and well characteristics required from initial fluid design through service quality and program implementation to well completion. The rigorous HTHP qualification tailors the fluid solution for optimal properties with products based on imperative data and real world performance. The scientists at the Newpark Technology Center’s laboratory use methodical techniques to formulate products and systems with advanced laboratory design techniques and a field-focused outlook. The operations manager provides a fluid program encompassing the design and operation that can withstand these hostile environments allowing for total service quality. During operations, the onsite engineering staff implements the drilling program with competencies, procedures, and plans being quickly tested. Timely decisions based on wellsite conditions are critical.
Evolution fluid remains stable, drills HPHT wells to 420°F, Cooper Basin, Australia: An operator in the Cooper Basin with no unconventional High Pressure High Temperature (HPHT) shale experience sought a reliable, robust drilling fluid capable of withstanding temperatures in excess of 420°F. Interested in a water-based solution, the operator asked Newpark about the capabilities of the Evolution system.
Novel water-based drilling fluid for HP/HT wells, Northern Italy: Well construction in deep HP/HT wells has been a major challenge over the years. The conventional understanding was that best results were obtained when low-toxicity, oil-based drilling fluids were used to address the adverse drilling conditions. However, the motivation to overcome the constraints related with this type of well while ensuring better performances and an enhanced environmental protection has led to research and the development of an innovative solution: a high-lubricity, water-based drilling fluid that could prove to deliver the desired results.