Challenging Wellbore Cleanouts With Coiled Tubing Made Easy With Computer 
Modeling Technology

Nasr‐El‐Din, Hisham A.; Alanazi, Mohammed M.; Balto, Abdulelah Adel; Proctor, Robert W.; Saleh, Raed

doi:10.2523/100129-ms

Proceedings of SPE/ICoTA Coiled Tubing Conference &Amp; Exhibition 2006

DOI: 10.2523/100129-ms

|View full text |Cite

Challenging Wellbore Cleanouts With Coiled Tubing Made Easy With Computer Modeling Technology

Hisham A. Nasr‐El‐Din¹,

Mohammed M. Alanazi²,

Abdulelah Adel Balto³

et al.

Abstract: TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractWell bore cleanouts have been performed for many years with coiled tubing and it may be said that the cleanout operation is one of the most routine services performed in the coiled tubing industry; but until recently design was no more than a rule-ofthumb approach. Sufficient information is now available to facilitate informed decisions and achieve reliable engineering solutions, utilizing a sophisticated particle transport model.A methodical thought process,… Show more

Help me understand this report

Search citation statements

Order By: Relevance

Paper Sections

Select...

Citation Types

Supporting

Mentioning

Contrasting

Year Published

2009

2013

Publication Types

Select...

Other3

Relationship

Self Cite0

Independent3

Authors

Journals

Cited by 3 publications

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

Simulation of Liquid Unloading from a Gas Well with Coiled Tubing Using a Transient Software

Salim¹,

Li²

2009

SPE Annual Technical Conference and Exhibition

View full text Add to dashboard Cite

Unloading gas wells is one of the most common applications for coiled tubing (CT). Despite the large number of jobs completed, fundamental questions about the optimum gas lift rate, run-in-hole speed and how much nitrogen is required remain. This is because the unloading process is not steady state, and the commonly used CT computer simulations can only model steady state flow.This paper describes transient software that has been developed and used to determine the nitrogen volume and cleaning time required when optimizing the process of liquid unloading from a gas well with CT.Based on experimental test results with a full scale flow loop, a critical gas velocity model was developed. This model determines how much liquid can be lifted for a given gas rate under varying operating conditions. It also determines the minimum gas rate required for complete liquid unloading. Several examples are presented which illustrate the transient characteristics of the liquid unloading process. A few field cases illustrate the benefits of using the transient model and some problems with conventional design methods.

show abstract

Simulation of Liquid Unloading from a Gas Well with Coiled Tubing Using a Transient Software

Salim¹,

Li²

2009

SPE Annual Technical Conference and Exhibition

View full text Add to dashboard Cite

show abstract

Performance Evaluation of a New Transient Two-Phase Flow Model

Teixeira

Fan

2012

IADC/SPE Drilling Conference and Exhibition

View full text Add to dashboard Cite

Transient gas-liquid flow is a common phenomenon in the drilling, workover and gas/oil production processes. Any change in the operating conditions at the inlet or outlet will introduce a transient response. Operations such as liquid unloading, under balanced drilling with gasified fluid, well control, cementing, hole cleaning, pipeline startup and blowout may never reach a steady state. In order to simulate the flow system, several transient two-phase flow simulators have been developed in the past. However, these models are based on the two-fluid model approach. They are complicated and time consuming to run since they treat the gas and liquid phase separately in terms of pressure, temperature and velocity. In this paper a new transient two-phase flow model has been developed. In each time step, the two-phase flow regime, liquid holdup and pressure gradient are estimated with the empirical correlations which are well developed for the steadystate flow. A drift-flux equation was introduced to close the system. The model was validated against data collected from the public literature, field operations, and other transient software. Several field cases are used to illustrate the transient nature of pipeline production, underbalanced drilling (UBD), sand cleanout, and liquid unloading. The benefits of using the transient simulation for the operational design, training and job execution are also discussed.

show abstract

Case History: Sand Handling and Hydrocarbon Containment During a Coiled Tubing Cleanout of a Live Deepwater Well

Peruzzi

Gagen

Reynolds

et al. 2013

SPE Annual Technical Conference and Exhibition

View full text Add to dashboard Cite

Procedures, photographs, diagrams, results and recommendations are shared from an operation to remove sand plugs from a high pressure deepwater well with a failed lower completion. Specific recommendations minimize risk and provide for the safe handling of sand on the surface as the oil passes below bubble point pressure and undergoes rapid expansion. This paper includes photos, diagrams and lessons learned from an operation conducted during the month of December 2011.Removing sand plugs from a live well entails multiple risks. As the hydrocarbon is circulated to surface gas will evolve and expand rapidly, increase the velocity of the mixture and pose the risk of loss of containment due to erosion, especially if sand is entrained within the mixture. Any interruption to surface handling of wellbore fluids and sand creates the risk of stuck coiled tubing. Coiled tubing stuck inside production tubing in a live well would result in an unwelcome and probably difficult fishing job. Literature ReviewA number of papers on coiled tubing cleanouts are provided in the attached references. However none of the papers specifically address the safe handling of sand on surface. SPE 166531 Risks and Mitigations.Risks and mitigations are outlined below. RiskMitigations Flammable Hydrocarbon Gas Equipment layout allowed all liquid flowing out of the well to be contained in pressurized tanks with venting to the production platform vapor recovery unit or flare. Hydrocarbon ContaminationAll liquids were contained in pressurized tanks. The well was maintained hydrostatically overbalanced by use of the coiled tubing choke to keep the well from flowing. Sticking the Coiled TubingMultiple flow paths and redundant equipment minimized the chance of shut-in. The rate of penetration of sand plugs was synchronized with purging of the sand buster.Provisions were made to inject additional liquid (drill water) upstream of anticipated plugging points such as the sand busters. Erosion of Surface Equipment.The well was never allowed to flow, so the maximum rate was dictated by the circulation rate of the coiled tubing. Much of the sand was removed upstream of the bubble point. Multiple vessels allowed for multiple pressure steps. We had multiple spare chokes as well as a complete spare choke manifold (on a standby boat). Damage of CT Pumps by Solids 800 barrels of brine (4 times tubing volume) were on hand to allow us to dispose of used liquids. Extra tanks were provided for settlement of solids for recycle of brine. Planning.The same contractor, Schlumberger, operated the coiled tubing unit and the flow-back equipment. This helped ensure close communication during planning and execution. Bronco provided sand buster equipment and personnel. Emphasis was placed on the need for close communication and coordination. Extra supervisors were hired to ensure the operation went smoothly and folks had adequate rest. Schlumberger modeled flow in the surface equipment to ensure rates would stay below erosive velocities at the planned circulation rates. All con...

show abstract

scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.

Contact Info

customersupport@researchsolutions.com

10624 S. Eastern Ave., Ste. A-614

Henderson, NV 89052, USA

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Blog Terms and Conditions API Terms Privacy Policy Contact Cookie Preferences Do Not Sell or Share My Personal Information

Made with 💙 for researchers

Part of the Research Solutions Family.

Challenging Wellbore Cleanouts With Coiled Tubing Made Easy With Computer Modeling Technology

Cited by 3 publications

References 4 publications

Simulation of Liquid Unloading from a Gas Well with Coiled Tubing Using a Transient Software

Simulation of Liquid Unloading from a Gas Well with Coiled Tubing Using a Transient Software

Performance Evaluation of a New Transient Two-Phase Flow Model

Case History: Sand Handling and Hydrocarbon Containment During a Coiled Tubing Cleanout of a Live Deepwater Well

Contact Info

Product

Resources

About