Multi-finger caliper tools are widely used for inspection of casing inner wall condition, particularly for determining wear, corrosion, deformation and scaling. The maximum pipe wall penetration, and hence metal loss, inferred from this method is greatly dependent on the casing inner diameter value (provided by casing manufacturer) used as a reference. Evidence of overestimated casing wear, including new completions, has raised the question around the validity of such interpretations.
Most of the casing is manufactured to API 5CT (ISO 11960) standard. The manufacturer‘s specification has an associated tolerance on casing outer diameter and thickness that is then used in the multi-finger caliper logs interpretation. The tolerance for casing with outer diameter (OD) greater or equal than 4.5″, is between -0.5% and +1% of OD. The pipe wall thickness tolerance ranges between manufacturer's nominal thickness and 12.5% metal loss.
The calculation of casing internal diameter (ID) tolerance is a difficult task as this is controlled by the casing mass tolerance which in practice is not easy to measure. To overcome the challenge, we implemented a new approach of calculating the minimum and maximum casing inner diameter and then using the ID tolerance as a reference for multi-finger caliper logs interpretation.
This approach has been tested with field data, and shows good correlation to actual casing inner diameter measurements performed at surface and is used as a baseline for new casing strings.
This paper will describe in detail the approach taken and compare the difference between interpretation outcomes with and without using the casing inner diameter tolerance. The benefits of calculating casing inner diameter tolerance and applying it to multi-finger caliper log interpretation results will be backed up with evidence from field log data acquired in ACG.
This paper discusses a new and general method of backup cutter layout to extend bit life without sacrificing rate of penetration and two field case studies. This method includes the following aspects: Ensuring backup cutters do not cut or only partially cut when their primary cutters experience little to no wear and when the depth of cut of the bit does not exceed an expected value. This aspect is enabled by allowing backup cutters to have a minimal critical depth of cut that is greater than the depth of cut of the primary cutters. Ensuring backup cutters act as major cutters when the primary cutters' wear depth is equal to or greater than the underexposure of the backup cutters. This aspect is enabled by allowing each backup cutter be rotationally behind its primary cutter by approximately 180° or greater. The underexposure of each backup cutter relative to its primary cutter is carefully calculated based on the primary cutter's wear and drilling slope.
Ensuring backup cutters do not cut or only partially cut when their primary cutters experience little to no wear and when the depth of cut of the bit does not exceed an expected value. This aspect is enabled by allowing backup cutters to have a minimal critical depth of cut that is greater than the depth of cut of the primary cutters.
Ensuring backup cutters act as major cutters when the primary cutters' wear depth is equal to or greater than the underexposure of the backup cutters. This aspect is enabled by allowing each backup cutter be rotationally behind its primary cutter by approximately 180° or greater. The underexposure of each backup cutter relative to its primary cutter is carefully calculated based on the primary cutter's wear and drilling slope.
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. As the sealing sleeve wears, pressure is actively applied to force the element against the drillpipe to maintain consistent seal performance. The device varies hydraulic pressure on the seal to compensate for wear and accommodate passage of wear- inducing tool joints.
Matsumoto, Keishi (Nippon Steel and Sumitomo Metal Corporation) | Sagara, Masayuki (Nippon Steel and Sumitomo Metal Corporation) | Miyajima, Makoto (Nippon Steel and Sumitomo Metal Corporation) | Kitamura, Kazuyuki (Nippon Steel and Sumitomo Metal Corporation) | Amaya, Hisashi (Nippon Steel and Sumitomo Metal Corporation)
Oil country tubular goods (OCTG) casing and liner wear is a critical problem in today’s drilling environments. To put in place practical countermeasures, it is important to understand its mechanism. This paper presents tribological and electrochemical experiments by use of various OCTG casing materials and environmental liquids, along with the in-situ observation and analysis of the rubbing interface. The results revealed that corrosion-resistant alloys (CRAs) showed an adhesive wear mechanism with relatively high wear rates, whereas low-alloy steels showed an abrasive or a corrosive wear mechanism with mild wear rates. The wear rate had a clear correlation with corrosiveness, where the wear rate increased as corrosion current densities decreased. In-situ observation exhibited that corrosion products c-FeOOH or Fe3O4 were generated and simultaneously scraped by sliding in the case of carbon steel, whereas no corrosion products were generated in the case of corrosion-resistant alloys. In conclusion, CRAs tend to have metal-to-metal adhesion (scuffing) with iron-based tool material, resulting in a high wear rate. However, low-alloy-steel casing can avoid adhesion by oxidizing its surface, resulting in a mild wear rate.
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. 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. By balancing the tradeoffs in conventional material performance, nanolaminated materials have the potential for broad application as surface coatings, claddings, bulk materials, or as near-net-shape parts. The deposition process can be controlled to produce nanoscale layers with unique interfacial properties resulting in enhanced corrosion-resistance, elastic-modulus, strength, hardness, and fracture-toughness combinations uniquely different from conventional material processing.
ABSTRACT: Cerchar abrasion index (CAI) is commonly used to represent rock abrasion for estimation of bit life and wear in various mining and tunneling applications. The test is simple and fast, but there have been some discrepancies in the test results which are related to the type of equipment, condition of the rock surface, operator skills, testing procedures, and measuring the wear flat. This paper focuses on the estimation of CAI and investigates the impact of various parameters on that. Results of a limited Cerchar tests on a set of rock samples from different laboratories are analyzed to correlate rock properties data to CIA value, which every value indicate an abrasiveness classification. As a result of a literature review, it is concluded that the abrasiveness of a rock sample based on the CAI value is strongly correlated with uniaxial compressive strength (UCS) and brittleness of rock samples. Rock brittleness is a function of UCS and Brazilian tensile strength (BTS). Thus, collected data of these parameters were hired to develop and train artificial neural networks (ANN) as an artificial intelligence (AI) method for estimation of drilling tool wear using data of rock strength and brittleness as inputs. It is pursued by the application of pattern recognition which is achieved by ANNs.
In this research, artificial neural networks (ANN) are applied to predict drilling bit wear using collected and calculated data of rock abrasiveness, including uniaxial compressive strength, Brazilian tensile strength and rock brittleness.
This purpose is pursued by performance of pattern recognition as it is one of the major applications of ANNs. The final proposed neural networks produces the abrasiveness classification by receiving data of UCS, BTS and brittleness.
1.1. Wear and Rock Abrasiveness The wear is in many ways similar to the effect of harder minerals on softer ones and is easily represented by the scratch that the hard objects engrave in soft minerals. Plinninger et al., 2002, depicted that “Abrasive wear” is the predominant wear process in most rock types.
AbstractDuring subsea mining operations, minerals are extracted from the seabed, typically at about 2000m depth, and pumped with water through a riser pipe to a surface processing vessel. TechnipFMC, through its subsidiary Technip France, is the lead of a consortium comprising COMEX and DCNS which has been awarded a contract by BPIFrance to develop a pilot subsea mining system. The scope includes the development of a flexible riser. This flexible riser comprises an inner wear protection layer to resist the wear from the slurry, covered by a structure to withstand mechanical loads applied to the flexible during its lifetime.In order to select the most appropriate anti-abrasion material, a large scale bench test has been built to reproduce realistic flow in a piping system and compare wear on different materials; rubber, polyethylene and stainless steels. Complete analysis of the wear patterns has been conducted with the expertise of a laboratory. A statistical comparison between materials is presented. The response to wear, depending on material, geometry and position, is better known. One of the materials shows much better wear resistance than the others and is selected for further development.The next step is the development and qualification of the manufacturing process for the wear protection layer. This process has to be as much as possible compatible with current flexible pipe manufacturing plant. Parameters such as thickness, diameter or length of the layer should be adaptable according to needs. The compatibility with the pipe mechanical structure has to be tested as well. To meet these requirements, existing manufacturing processes are limited. At the time of writing this paper, different manufacturing methods to incorporate this wear protection layer within a continuous industrial flexible production are currently under investigation. Several prototypes will be realized for each manufacturing step. Prototyping is under test and will be presented in a forthcoming presentation.
AbstractMaintaining a safe offshore operating environment is becoming increasingly difficult, as producers are pushing their equipment harder to achieve their productivity goals. In this context, maintaining the required safety environment requires a robust lubrication program that can protect equipment from extreme operating conditions and maximize that equipment's availability, thus reducing the need for human-machine interaction (HMI) and enhancing the safety of maintenance personnel.This paper will provide guidance on how operators can maintain a high standard of operational safety in the face of the ever-increasing complexity and challenging conditions of offshore operating environments. The paper will outline how producers can design a robust lubrication approach - incorporating key lubricant technology considerations and expert technical services to help enhance the reliability and availability of their equipment.First, the paper will highlight what producers should look for in lubricant formulation. While synthetic lubricants are well understood to be the best performing lubricants, performance among synthetics can vary depending on formulation. And, while some operators may be hesitant to adopt synthetic lubricants due to traditional preferences or cost considerations, this paper will provide a data- based argument for why synthetic lubricants are a must for any best-in-class safety program.In addition to lubricant technologies, producers must also have the right equipment maintenance processes in place to identify and respond to equipment performance issues before they become a problem. The most important of these services is used oil analysis. This paper will briefly highlight the value of this service and outline specific considerations to help operators optimize their oil analysis programs.Backed by insights and data from laboratory testing and real-world performance, offshore professionals will be provided with the latest information and best practices they need to further optimize their maintenance program as they work to deliver a best-in-class safety environment for their workers.
Neale, Peter (Continental ContiTech Industrial Fluid Solutions) | Nagy, Tibor (ContiTech Rubber Industrial Ltd) | Grepaly, Istvan (ContiTech Rubber Industrial Ltd) | Tóth, Péter (CFD.HU Ltd.) | Kristóf, Gergely (Department of Fluid Mechanics, Faculty of Mechanical Engineering, Budapest University of Technology and Economics) | Csobán, Attila (Department of Machine and Product Design, Faculty of Mechanical Engineering, Budapest University of Technology and Economics)
AbstractThe results of a long term abrasion test on 10" hoses were compared to flow simulation based abrasion calculations. An impact angle dependent small scale abrasion test was carried out on the rubber liner material to establish input data for abrasion simulation. The simulation proved to be very sensitive to the dependence of the impact angle on the abrasion rate, particularly at low impact angles. Three different lining materials were applied in the full scale test: rubber, a proprietary plastic liner and rubber with built in hard steel rings using a purpose built machine. The abrasion rate increased in the following order: armored liner, rubber and plastic, although the plastic had better Schopper abrasion than rubber.