Layer | Fill | Outline |
---|
Map layers
Theme | Visible | Selectable | Appearance | Zoom Range (now: 0) |
---|
Fill | Stroke |
---|---|
Collaborating Authors
Numerous continuous-length tubular service concept trials and inventions paved the way for the creation of present day CT technology. The following discussion outlines some of the inventions and major milestones that directly contributed to the evolution of the continuous-length tubular products used in modern CT services. The origins of continuous-length, steel-tubing technology can be traced to engineering and fabrication work pioneered by Allied engineering teams during the Second World War. Project 99, code named "PLUTO" (an acronym for Pipe Lines Under The Ocean), was a top-secret Allied invasion enterprise involving the deployment of pipelines from the coast of England to several points along the coast of France.
- Asia (1.00)
- Europe > United Kingdom (0.65)
- North America > United States > Texas (0.46)
- Europe > United Kingdom > North Sea > Central North Sea > Central Graben > Block 21/10 > Forties Field > Forties Formation (0.99)
- Asia > India > Rajasthan > Cambay Basin (0.99)
- Asia > India > Gujarat > Cambay Basin > Jotana Field (0.99)
- (3 more...)
- Information Technology > Knowledge Management (0.50)
- Information Technology > Communications > Collaboration (0.40)
The CT injector is the equipment component used to grip the continuous-length tubing and provide the forces needed for deployment and retrieval of the tube into and out of the wellbore. Figure 1.5--CT injector and typical well-control stack rig-up (courtesy of SAS Industries Inc.). The tubing guide arch assembly may incorporate a series of rollers along the arch to support the tubing or may be equipped with a fluoropolymer-type slide pad run along the length of the arch. The tubing guide arch should also include a series of secondary rollers mounted above the CT to center the tubing as it travels over the guide arch. The number, size, material, and spacing of the rollers can vary significantly with different tubing guide arch designs. For CT used repeatedly in well intervention and drilling applications, the radius of the tubing guide arch should be at least 30 times the specified OD of the CT in service. This factor may be less for CT that will be bend-cycled only a few times, such ...
- Europe (1.00)
- Asia (1.00)
- North America > United States > Texas (0.47)
- Europe > United Kingdom > North Sea > Central North Sea > Central Graben > Block 21/10 > Forties Field > Forties Formation (0.99)
- Asia > India > Rajasthan > Cambay Basin (0.99)
- Asia > India > Gujarat > Cambay Basin > Jotana Field (0.99)
- Information Technology > Knowledge Management (0.50)
- Information Technology > Communications > Collaboration (0.40)
Abstract Most coiled tubing (CT) interventions are performed in a rigless environment. In fact, this is one of the important drivers for the widespread acceptance and continued growth of the technique for well servicing, especially in the offshore domain where the logistical costs are higher and operational challenges are more complex. Unlike land-based CT operations where integration is straightforward, the issues of equipment packaging for offshore integration is daunting. Overcoming limitations of crane-load lift capacity and deck space constraints are just part of the problem. Offshore CT units (CTU) are typically packaged as separate modules with components that require integration before any well intervention activity can begin. Rig up and operational efficiency are important design considerations for offshore CTU packages, but overall safety and regulatory compliance are of paramount concern. A new CTU configuration designed to meet the stringent demands of offshore CT operations was recently introduced. The design focused on key integration and HSE issues relating to the rig-up process. Results from more than 500 jobs performed during a 2-year period, in far eastern offshore environments indicated significant improvements in overall operational efficiency. In addition, the new designs met predefined HSE performance objectives, particularly during equipment rig-up phase. Introduction Since 2001, there has been a tremendous growth in the size of CTU service fleets. Based on an ICoTA survey, the total number of working CT units has grown from roughly 840 units in February 2001 to slightly more than 1,050 CTUs available worldwide in 2004. In March 2008, estimates for the global fleet size were reported at 1,500 units. During this period of growth, the scope of work for CT services also has continued to expand. This expansion brought some notable developments. First, the number of interventions increased in environments where standard CTU equipment packages were not intended to service, particularly in some offshore installations. The number of service quality incidents also increased, which resulted in several service delays. The failures are related to some degree to equipment packaging, but more so to the increased complexity in the performing these operations and to inexperienced younger service crews. Because most CTUs are provided by 3 or 4 large equipment manufacturers, the designs are very similar. Until recently, there was little need to radically evolve equipment designs. However, the well servicing environment is calling more and more for fit-for-purpose units, particularly offshore. From an equipment standpoint, addressing the challenges of offshore CT interventions currently is being approached in several effective ways and this has been the subject of previous discussions by Cochran (2008) and Andreassen (2004). The majority of these new equipment packages are customized insofar as specifications and features are concerned. However, the primary driver for customization is operational efficiency and overall safety.
- North America > United States > Texas (0.28)
- Asia (0.28)
Coiled tubing (CT) well intervention and drilling operations require that the continuous-length tube be subjected to repeated deployment and retrieval cycles during its working life. The tubing stored on a service reel is deployed into the wellbore to the designated depth and then retrieved back onto theservice reel. All of the aforementioned items act on the tube body to some degree during any CT service and contribute to the eventual mechanical failure of the tubing. To ensure safe and reliable well intervention and drilling operations, the user must understand the unique behavior of CT to minimize the possibility of tubing failure. Numerous decisions must be made throughout the working life of a CT string to maximize the remaining life. From this approach, the decision to retire the tubing must be made on the basis of current tube conditions, service history, and the anticipated service loading. Fatigue is generally considered to be the single major factor in determining the working life of CT. The deployment and retrieval of the continuous-length tubing string require that the tube be subjected to repeated bending and straightening events, commonly referred to as "bend-cycling." The amount of strain imposed upon the tube body during the bend-cycling process is considered to be enormous, in many cases on the order of 2 to 3%. When subjecting the CT to this type of fatigue cycling, the stress and/or strain fluctuations to failure may be estimated using conventional axial fatigue life prediction approaches.[1]
- Information Technology > Knowledge Management (0.40)
- Information Technology > Communications > Collaboration (0.40)
The coiled tubing (CT) injector is the equipment component used to grip the continuous-length tubing and provide the forces needed for deployment and retrieval of the tube into and out of the wellbore. The injector assembly is designed to perform three basic functions: * Provide the thrust required to snub the tubing into the well against surface pressure and/or to overcome wellbore friction forces. Figure 1 illustrates a typical rig-up of a CT injector and well-control stack on a wellhead. There are several types of counter-rotating, chaindrive injectors working within the industry, and the manner in which the gripper blocks are loaded onto the tubing varies depending on design. These types of injectors manipulate the continuous tubing string using two opposed sprocketdrive traction chains, which are powered by counter-rotating hydraulic motors.
- Information Technology > Knowledge Management (0.40)
- Information Technology > Communications > Collaboration (0.40)