A research initiative was launched to investigate different methods to enable a PDC shearing element to fully rotate while drilling to increase overall cutting efficiency and bit life. The recent introduction of a new rolling-cutter PDC bit that uses 360 of the diamond edge has delivered positive results in field trials. When drilling with a conventional PDC bit, the percentage of cutter that contacts the formation will vary depending on several factors. However, in most cases, only 10 to 40% of the cutter will be used to actually shear the formation. The remaining 60 to 90% of the cutter is locked into the bit body and remains unused during the run.
Drillpipe doesn't last forever, but a Houston-area startup company says it has developed a way to make it last significantly longer. WhiteHorse Technology calls its service product wear bands, which is an adaptation of a technology invented in the 1930s called hardbanding. Hardbanding is a welding process that is still used today to protect steel tool joints from excessive wear and tear by coating them with a sacrificial metal material. This makes it possible to add a protective layer of metallic coating to the midsection of a drilling pipe without negatively impacting its metallurgic properties--an application breakthrough that WhiteHorse claims no other firm does. The company reports that its wear-banded pipe experiences lower downhole friction and also allows for a greater weight-on-bit to be used, which results in faster drilling speeds.
Precise casing-wear prediction is important for improving well integrity and longevity, while simultaneously making casing designs more cost-effective. Currently, there are no known and commonly accepted guidelines available in the industry. Several studies have been presented in literature over the past couple of decades that proposed various methods for estimating the downhole wear in casings. However, the results of all such efforts have been mixed. Predicted values of casing wear using wear models failed to accurately match the wear logs from the wells when scaled up to the field level.
Modumetal introduced its zinc-based alloy, NanoGalv, part of its new class of nanolaminated materials with broad application in structural parts, coatings and claddings, thermal barriers, and armor. NanoGalv outperforms conventional galvanization processes by more than seven times, reducing the need for replacement parts over the life of metal components and associated risk of wear and failure. "Nanolaminated materials" refers to a class of materials comprising nanometer-scale particles deposited in layers that vary in composition, phase, microstructure, or a combination thereof. To create nanolaminated coatings, zinc-based metallic alloys are applied electrochemically, at room temperature, to steel substrates to enhance corrosion resistance and base-material-mechanical properties. The unique metal attributes achieved by nanolamination not only impart improved performance characteristics but also overcome intrinsic-material-property tradeoffs (i.e., hardness and toughness, creep and fatigue, corrosion, and wear) that are typically encountered in homogeneous materials.
Cutting & Wear's SupaCutt range of hardfacing rods are used to hardface mills for cutting steel and other materials downhole. They are made up of crushed tungsten carbide in a brazing alloy. When deposited on a mill, the brazing alloy is melted, bonding the tungsten carbide fragments to the tool. This forms a coarse cutting structure able to cut through obstructions downhole. The industry standard crushing process generates poorly shaped fragments that can be flaky in character and from which the better-shaped fragments are then selected to be used in the manufacture of the rods.
Reducing vibrations not only extends bit life, but also helps extend the life of other BHA tools and deliver smoother drilling performance for improved borehole quality.The bit includes StayTrue shaped-diamond-insert elements that stabilize the bit to reduce lateral vibrations by more than 90%, mitigating vibration-induced damage to both the bit and highly sensitive BHA components containing electronics. The bit's long-life cutters generate 30% less heat than standard PDC cutters. This reduces wear and premature weakening of the cutters that is often a result of excessive heat generation. The bit's elements and cutters are incorporated into a newly designed body comprisin a matrix material that resists cracking and is capable of handling extreme operating loads that would damage conventional PDC bits.
Managed Pressure Drilling (MPD) that depends on a rotating control device (RCD) is benefiting from a specialized subsea innovation that improves performance and eliminates the conventional RCD altogether for subsea applications. In deepwater environments, the Active Control Device (ACD) from AFGlobal offers a significant departure from conventional RCDs with a purpose-built, nonrotating, hydraulically controlled sealing sleeve around the drillpipe. The ACD, a component of the broader riser-gas-handling system, is American Petroleum Institute 16RCD-qualified to isolate and seal off the top of the riser to divert mudflow during MPD operations. The unique sleeve is a comolded element comprising an enhanced urethane matrix reinforced with a durable polytetrafluoroethylene inner shell. As the sealing sleeve wears, pressure is actively applied to force the element against the drillpipe to maintain consistent seal performance.
A hybrid model based on Physics of failure and Data-driven algorithms is developed that can estimate remaining useful life of production casing (well barrier). The state of integrity of the well barrier is assessed by updating the reliability under operational loads.
The interactions between the casing and surrounding formation, and effects of tribocorrosion on the casing are considered. Tribocorrosion is the process of degradation of a material resulting from a sequential process of (i) mechanical wear (due to sliding, friction, or impact) followed by (ii) a corrosive action of the surrounding environment. The model includes simulating casing wear due to drilling, and enhanced degradation due to conditions in the well.
The main capability of the model is to help well integrity analyst with insight of future health states of a monitored well. This is achieved in two main steps; the first being the offline module comprised of degradation models. The second is the pattern recognition based on well log and features mapping, and estimation of remaining useful life of well barrier. The production casing grade P-110 undergo reduction in strength due to wear during drilling, induced stress and hydrogen induced cracking. The remaining useful life is calculated for the depths of interest and time.
A comparative analysis is carried out using the industry standard soft-string model versus a more comprehensive stiff-string model to estimate wear. The paper presents a unique approach to predict the remaining useful life of a well barrier and the dynamic state of the well's operational integrity. The prediction is not solely based on statistical modeling but also incorporates barrier engineering and physics of failure in the model.
Liu, Yu (Shell International Exploration and Production Inc) | Kibbey, Justin (Shell International Exploration and Production Inc) | Bai, Yanbin (Shell International Exploration and Production Inc) | Wu, Xianping (Shell International Exploration and Production Inc)
Severe bit damage is a known issue in west Texas land drilling due to abrasive sand formation and interbedded hard stringers. Operational performance and rig cost are often impacted by penalty fee of bit DBR (damage beyond repairable), low ROP (rate of penetration) with worn bit, and inefficient decision-making on tripping. A real-time data analytics application is developed aiming to provide actionable information to operation to expedite decision making process.
A historical dataset of surface mechanics data and bit records is collected from 40 bit runs drilled in 2016 and early 2017. A hybrid data analytics procedure consisting of conventional physical modeling of drilling mechanics and supervised learning using machine learning technique is conducted to separate bit failure pattern from normal formation transition and drilling parameters adjustment. A metric based algorithm is constructed for real-time monitoring of bit drilling performance and early warning on bit cutter wear conditions.
A web-based real-time software is developed and field trialed on three wells with satisfactory results. Subsequent deployments in DART (Drilling Automation Remote Technology) center and field offices have been quickly rolled out for five rigs in west Texas. Positive feedback is generated from operation and engineers. Attributed to the success of agile development framework and adaptive software architecture, other advisory mode features such as motor life monitoring, smart-tripping evaluation, and sliding diagnosis etc. are under development.
The application discussed in this paper combines expert's domain knowledge with machine learning techniques and provides actionable information to support on-site operational decisions. The development and deployment of this application follows an agile mode innovation framework, through which operational need and technical solution are quickly bridged and tangible business value is able to be delivered in short term.