A New SBM for Narrow Margin Extended Reach Drilling

Abstract

Extended Reach Drilling (ERD) wells drilled nowadays can reach a step-out of 10 km (33,000 ft) and thus present many drilling challenges, including torque and drag, hole cleaning, wellbore stability, equivalent circulating density (ECD) management, lost circulation management, just to name a few. These challenges can severely limit the desired well depth or increase the operation time, particularly in deepwater environment. A new synthetic-based flat rheology drilling fluid (SBM) with new emulsifier and rheology modifier package has been designed for narrow margin ERD wells. This newly developed flat-rheology SBM utilizes a novel, single emulsifier to simplify fluid formulation, improve emulsion stability, enhance thermal stability, and provide surface wetting and fluid lubricity. This allows the system to be formulated for any ERD applications with mud weights up to 18.0 lb/gal and temperatures up to 350°F. In addition, the system uses a new rheology modifier that provides temperature-independent rheology profile for better hole cleaning, barite suspension, ECD management and lost circulation control. A recent field trial conducted in deepwater GoM indicated that the new system is easy to handle and provides good fluid performance in terms of drilling rate, ECD management, lost circulation control and hole cleaning. The SBM at one time was severely contaminated due to salt water flow but the fluid held together without any problems. Similar results on drilling performance were observed with another onshore field trial that used a non-synthetic-based fluid. This article describes the new flat-rheology SBM system with examples showing typical mud formulations, fluid properties, barite sag performance data, field test data and computer hydraulics simulation of ECD impacts.

Setting Free the Bear: The Challenges and Lessons of the Ursa A-10 Deepwater Extended-Reach Well

“…Conventional SBMs typically experience a significant reduction in rheological parameters such as yield point and low-end rheology at higher temperatures (with a lesser, but non-negligible, effect of pressure). This particular weakness has meanwhile been effectively addressed with the introduction of flat-rheology SBMs (van Oort and Friedheim 2004; Lee et al 2012). In fact, the Ursa A-10 drilling experience was the direct inspiration for the creation of these special mud systems.…”

“…In particular, any practices affecting downhole ECD should be carefully reviewed. The key to drilling a deepwater ERD well successfully is appropriate management of downhole ECDs within the available narrow drilling margin, which may be extended with borehole-strengthening techniques (van Oort et al 2009). Fig.…”

Machine Learning Model for Monitoring Rheological Properties of Synthetic Oil-Based Mud

“…The flat rheology topic is introduced to the drilling fluid research and field applications with newly developed materials due to its efficient performance . The flat rheology synthetic oil-based mud is one of the flat rheology mud generations that is utilized for harsh and critical drilling conditions for efficient drilling and hydraulic systems that will greatly affect the drilling cost. , The cost and fluid handling precautions are considered main disadvantages for this mud system in the drilling operations.…”

Rheological and filtration property evaluations of the nano-based muds for drilling applications in low temperature environments

“…The idea was to design a drilling mud that exhibits more thermally stable characteristics across a broad temperature conditions. This mud was initially designed for the offshore deep-water drilling applications (Davison et al, 1999;Friedheim et al, 2011;Knox et al, 2015;Lee et al, 2012;Rojas et al, 2007;van Oort et al, 2004;Young et al, 2012). Amongst the first to formulate this type of muds were Elward-Berry and Thomas, 1994, where they formulated the mud sample by mixing saltwater and polyglycerol as the continuous phase and added with some polymeric additives including starch, polyanionic cellulose, and bio-gum.…”