Johnson Engineering (United States)

Abstract The adage that "the easy oil is gone" underscores the need for continuous advancements in drilling technologies. Among these innovations is slim hole drilling, which has gained relevance across various applications, including casing drilling and mineral exploration. The objective of this paper is to identify and assess operational strategies for safely detecting and circulating gas influxes from a borehole to support the development of effective and reliable well-control procedures tailored to slim hole environments. The scenario in question involves a mineral exploration rig equipped with slick 70 mm (2¾ in.) OD drill rods drilling a 76 mm (3 in.) ID borehole to a depth of 1,600 m. Transient flow simulation tools were employed to evaluate the hydraulics and well-control phenomena associated with such a slim-hole configuration. Influx scenarios included fractured formations combined with lost circulation and the risks of encountering small high-pressure cavities in impermeable rock. Sensitivity analyses were performed to evaluate the effects of varying kick size and intensity. The reduced annular clearance between drill string and borehole introduces substantial differences from conventional drilling hydraulics and well-control principles. Simulations using conventional oilfield drilling fluids revealed that non-Newtonian fluids led to excessive equivalent circulating densities (ECD), making the use of solids-free Newtonian water-based fluids essential. Rotary speeds typical of slim-hole mineral exploration operations, up to 300 rpm, were shown to contribute an additional 0.36 SG (3 ppg) to ECD. Kick simulations revealed that standard well-control practices, such as immediate shut-in followed by the Driller's Method for circulating out a kick, were not optimal in slim-hole conditions. Depending on annular geometry and influx characteristics, a dynamic kill approach offered safer and more efficient control. The scenarios are based on a mineral exploration rig equipped with a 150 mm (6 in.) ID annular blowout preventer venting into a mud gas separator. Despite its limitations, transient simulations demonstrated that such minimal equipment is capable of managing the envisaged well control events. The findings supported the development of tailored well-control procedures, improving operational safety and reliability in such a complex environment. The use of transient flow simulations to evaluate well-control operations and equipment for slim-hole wells is described. The examples highlight how local geology dictates the well-control measures that need to be implemented. The findings demonstrate how modeling can guide equipment selection, procedure development, and training programs, enhancing preparedness for slim-hole drilling operations.

Congenital anomalies of the kidneys and urinary tract (CAKUT) are developmental defects affecting 1 in 465 live births and constitute 28% to 33% of neonatal ultrasound anomalies. CAKUT is a major contributor to chronic kidney disease in children and is the leading cause of end-stage kidney disease (ESKD) in this population, accounting for 40% to 50% of cases. Amniotic fluid volume reflects renal function. CAKUT that decreases amniotic fluid can result in serious complications. Although treatments such as amnioinfusion, vesicoamniotic shunting, and cystoscopy shows promise, they carry risks and uncertain long-term outcomes. This highlights the importance of further research to improve management of these conditions.

Reliability is what separates an “engineered” item from one that is simply “made” or “designed.” It generally requires some form of life prediction under specified conditions to establish a baseline, and then, the performance is compared to the baseline. Verification, validation, and uncertainty quantification (VVUQ) has long been part of engineering development, particularly for novel projects that precede the development of engineering design codes and standards or have significant risks, such as medical devices. The use of engineering simulations also requires VVUQ, with the amount of VVUQ being also relative to the risk and whether it is applied within existing engineering standards or not. Establishing reliability is not only due diligence for the design process but it is also needed by forensic engineers and other expert witnesses to ensure that their processes, particularly in using simulations, have the due diligence to prevent “garbage in/garbage out.” Looking forward, using VVUQ techniques with engineering simulations provides the framework for future use of VVUQ for artificial intelligence (AI) and machine learning (ML) in a legal context to demonstrate that the specific application is a reliable process, applied in an appropriate and reliable manner, and closes the gap between the numerical processes and the specifics of the case in question.

This study aims to evaluate via a case study the process in establishing post-construction performance goals and their perceived impact to a design and construction project team's culture.Performance goals were established from an iterative quantitative approach, while the impact to the design and construction team were evaluated by a qualitative method.Preliminary results appear to indicate a likely positive impact to a project team's culture, level of effort, and trust.Specifically, results may indicate a net positive impact from unambiguous post-construction performance goals to a project team's perception of its communication and overall project environment, reduction in traditional sources of process waste, and a positive impact to elements associated with cost, schedule, and quality.

Most existing buildings have sub-optimal heating, ventilation, and air conditioning (HVAC) controls, resulting in wasted energy and occupant discomfort. Retro-commissioning (RCx) addresses many of these issues, but it is a lengthy and highly customized process. Limited capabilities of existing building automation system hardware restricts the scope of most RCx projects. Incentive programs consider building automation system (BAS) hardware retrofits to be high-capital investments and do not allow them in typical RCx programs. This paper describes work that the authors are leading to facilitate technical and market innovation in the BAS industry to unlock large savings in existing commercial buildings through deep retrofits of BAS hardware and software. California and New York research projects are demonstrating BAS retrofits leveraging the American Society of Heating, Refrigeration, and Air Conditioning Engineers’ (ASHRAE) new Guideline 36 high performance sequences of operation to achieve greater than 20 percent whole building energy savings, while saving costs and reducing risk through streamlined processes and standardization across BAS manufacturer product lines and across implementation practices. This paper describes market barriers that impede achieving deep savings from BAS retrofits in custom incentive and traditional RCx programs and presents a new maximum potential BAS retrofit model that addresses these barriers. The new model leverages the authors’ efforts in market enablement through open standards, BAS industry partnerships, and tools for cost-effective scaling that includes tools for project screening, savings calculations, and measurement and verification (M&V). This approach is widely applicable and will be ready for at-scale implementation within two years.

The failure of coke drum anchor bolts is a demanding and recurring maintenance item for many delayed coking operators. While there are several factors that can contribute to these failures, some studies have demonstrated that significant stresses may result from thermal expansion of the drum under non-uniform thermal gradients. To address bolt failures, a restraint system that utilizes non-contacting anchor blocks has been developed and implemented for the first time on a set of operating coke drums. In this paper, the background of anchor bolt failures as well as the design and first implementation of the new restraint system are discussed.