More than 40 papers were presented at the Conference. The presentations were made at a number of technical sessions: Innovative Solutions and Latest Developments, Material Performance and Behavior, Milling and Drilling, CTD: Fracturing and Subsea.

 

Schlumberger and Talisman Malaysia paper “A Successful Application of Fiber-Optic-Enabled Coiled Tubing With Distributed Temperature Sensing (DTS) Along With Pressures to Diagnose Production Decline in an Offshore Oil Well”, presented by P.E. Parta, was quite an event of the first day of the Conference. The paper features a field example of a horizontal well in the South China Sea, where pressure and distributed temperature measurements enabled understanding of reservoir characteristics and fluid movement causing production hindrance in an offshore

horizontal well. The point-measurement nature of sensors made it difficult to make sense of collected data and interpret the events. But it recently evolved to include the capability of performing temperature measurements along the length of the wellbore, thus distributed temperature sensing. No longer just limited to a point measurement, this evolution becomes possible through the use of a fiber-optic enable CT string. By performing DTS measurements, characterization of the injectivity or productivity profile can be achieved.

 

Technical session “Material Performance and Behavior” was opened by Halliburton paper “Comparison of Computational Fluid Dynamics of Erosion in Coiled Tubing on Reel-to-Injector Flow Area” (M. Bailey et al), devoted to new opportunities of getting knowledge about the actual flow through the CT. In recent years computational fluid dynamics (CFD) is being used to gain further knowledge while saving the costs of capital and resource investment for testing. CFD can also generate flow patterns, fluid-flow velocity profiles, secondary-flow regimes, and erosion. This paper compares the actual data to the CFD generated solution. Once the data has been validated, the CFD solution can be used to enhance a CT predicting model.

 

The paper “Safer, Faster and More Reliable Operations With Next-Generation Offshore Coiled Tubing Unit” (R. Burgos et al, Schlumberger) highlights the need for fit-for-profit units, particularly offshore. Unlike land-based CT operations where integration is straightforward, the issues of equipment packaging for offshore integration is daunting. Offshore CT units (CTU) are typically packaged as separate modules with components that require integration before any well intervention acivity can begin. The current CTU is the product of evolution, based on review and analysis of service quality data and field user and customer input. Several innovations were incorporated into the design to deliver on the project objectives, including SQ incident reduction, rig-up time reduction, reduced logistic burden, maintainance cost reduction.

 

L. Castro from BJ Services presented a paper “Optimizing the Most Common CT Operations in the US: Findings From More Than 60 Composite Frac Plugs Underbalanced Milling Operations in the Piceance Basin”. The advent of multi-zone stimulation techniques has created an increasing need for zonal isolation devices, such as bridge and frac plugs. Milling composite frac plugs (CFP) using coiled tubing and positive displacement motors (PDM) is one of the most common and effective methods in the industry. Where formation properties allow, overbalanced CFP milling is routinely performed with high degrees of success. However, underbalanced milling operations that use nitrogen as a circulation aid pose additional challenges. This paper presents the lessons learned from over sixty underbalanced CFP milling operations performed in the Piceance Basin. The results shown are uniquely relevant due to the fact that the operations involved in this study were performed within the same field, using the same type and size of PDM, mill, CFP, and CT.

 

The poster presentation “Working With Coiled Tubing in H2S and CO2 Wells: A Global Perspective” (R. Hampson et al, Halliburton) is focused on various problems associated with working with CT in H2S and CO2 wells and the best practice taken from locations working regularly with H2S and CO2 in locations all over the world. Oilfield production fluids containing the acid gases can be corrosive to CT because of the resultant lowering of the pH of the aqueous phase. This paper shows the equipment, chemical inhibitor, quantity and method of inhibitor application, and other precautions taken to carry out the work safely and successfully. An alternative approach to using SSC inhibitors has been demonstrated in Kazakhstan and Canada. Before any subsequent perforating work, the well is bullheaded to push any H2S back into the reservoir, allowing CT operations to be done in clean fluid that has been pumped into the well, which prevents corrosion.

 

2009 CTWI Exhibition featured more than 65 leading companies of the industry, including National Oilwell Varco, Baker Hughes, Global Tubing, Aker Solutions, AnTech, Amkin Technologies, which presented their innovative solutions and latest developments. NOV Hydra Rig introduced the Merlin Control System – next generation of Coiled Tubing Unit controls. It’s a hydraulic powered, computer conrolled system that provides improved operational performance and safety for coiled tubing unit operation, diminishing human-factor aspect.

 

The event was traditionally held on a very high level. Despite contraction of the industry, cutbacks in budgets and reduction in personnel, specialists try to keep up with new technologies and equipment. And it’s not surprising, for it is innovative solutions that will help to face the challenge of present-day economic environment, to do the work in least possible time and achieve cost efficiency in services.