哈里伯顿经典之作：Swellpacker领衔膨胀封隔

Today’s oilfield requires operators to find simpler, safer, and more stable downhole technologies. The Halliburton Easywell Swellpacker isolation system is an innovation that meets all of these criteria. The technology is based on the swelling properties of rubber in hydrocarbons or water, or in both. It swells up to 200%, sealing the annulus around the pipe to achieve effective zonal isolation. Once deployed, the rubber retains its flexibility, allowing the Swellpacker isolation system to adapt to shifts in the formation over time, retaining the integrity of the seal. Its self-healing properties make this a truly innovative technology for all zonal isolation applications. It is a bonded to pipe product that can be delivered with any element length depending on the basepipe length. Since the rubber is bonded to the basepipe, it is extremely robust and can hold significant differential pressures.

The Swellpacker system can be used in cased or openhole environments. In some openhole applications, operators may be able to avoid cementing and perforating altogether, reducing the expense associated with these operations. By reducing well construction costs, saving rig time, and isolating producing zones, the Swellpacker system helps enable previously unachievable levels of oilfield performance.

Cementing Support

For well integrity issues, the Swellpacker isolation system can also be used to complement the primary cement job.The system provides comprehensive long-term zonal isolation, increasing the productive life of the well and minimizing the potential of an expensive workover operation. This combination of proven technologies provides an effective means to address both micro annulus concerns and incomplete cement sheath issues.

Swelling Delay Systems

To ensure that the oil or water contained within the well fluid does not affect the packer while it is run into the hole, Halliburton has engineered several systems that can delay the swelling process. These enable control of the elastomer swelling process as the setting time can be tailored according to the customer’s needs, mitigating the risk of premature setting while optimizing the operating envelope.The systems include polymers with built-in slower swelling properties and a variety of applied diffusion barriers. Customizing a design with either of these options, or using in combination, allows for creation of a well-specific engineered product.

End Ring Design

In addition to the elastomer compound development, Halliburton continues to innovate in all areas of the Swellpacker isolation system design, including the end rings.These important components assist in increasing the differential pressure capability and guide the packer when run into the hole. Depending on the application and metallurgy requirements, the design can be anchored using set screws, a crimping process or welding. In addition, Halliburton has developed a new type of end ring. The K2 end ring protects the rubber element while running in hole and further eliminates element extrusion once the packer is set. One of the benefits of this unique end ring is the ability to shorten the tool length, while maintaining differential pressure. It also increases absolute differential pressure performance of the tools with testing done up to 15,000 psi across the packer.

Swellpacker Cable System

The Swellpacker system can be delivered with a unique cable feed-through option which enables the passage of single or multiple control lines and flat packs for downhole monitoring, chemical injection and SmartWell completion systems without the need to cut the cables or lines. This removes the requirement for cable splices, control line cuts and cable stripping, greatly reducing the risk of failure. It provides an annular seal in cased and open hole, and a seal around the control lines or flat packs capable of holding differential pressure. Installation of the cables through the Swellpacker system is performed on the rig floor at the time of running the completion and requires no extra rig time.

Installation

To install the systems, simply perform standard pre-job checks, then run in hole as part of the reservoir completion string or liner system. At that point either produce the well to begin the swelling process or allow the current well fluid to swell the packer systems prior to operations or circulate down the designed swelling fluid. The simplicity of the operation means that specialized installation personnel are not required. For the cable design, Halliburton provides the installation tool that fits easily on the rotary table and installs the control cable or flatpack through the packer.

Features

• Manufactured on any oilfield tubular;
• Suitable for cased and open holes;
• Robust construction;
• No moving parts;
• Spliceless cable feed-through option;
• Self-healing, interventionless technology;
• Can be run in most all fluid environments;
• Multiple polymers available to provide oil-swelling (OS);
• water-swelling (WS) and hybrid-swelling (HS) solutions;
• Engineered swelling delay system.

Benefits 

• No specialist operator required for installation;
• Casing integrity is maintained;
• Ideal for irregular borehole geometry;
• Alternative solution to cementing and perforating in;
• certain applications;
• Complements cement to resolve well integrity issues;
• Helps reduce operational risk;
• Isolates producing zones more effectively;
• Helps reduce well costs and rig time;
• Cable feature increases system reliability by eliminating cable;
• splicing and enables openhole SmartWell completion systems.

Applications 

• Open and cased hole isolations;
• Stimulation placement;
• Open and cased hole straddles;
• SmartWell completion systems;
• Monitoring and chemical injection;
• Water control;
• Multilaterals;
• Stand-alone screen sand control;
• Compartmentalization for screen/ICD completions;
• Gravel pack isolation;
• Well construction.

Application

 OVERVIEW 

A major operator in Vietnam decided to run and cement a 13 5/8-in casing inside 16-in. liner for the first time in its high pressure/ high temperature (HP/HT) field. Halliburton determined severe fluid losses could be expected due to the very tight annular tolerance between the 13 5/8-in. casing and 16-in. liner. The primary objective was to provide a good shoe to drill ahead and a secondary barrier for added zonal isolation should the cement column be impacted by the high equivalent circulating density (ECD) and the low pressure zone below the casing shoe.

Halliburton proposed using its Swellpacker isolation systems to help ensure well integrity. Since drilling operations were ongoing, the operator needed to have the equipment delivered to the wellsite in only six weeks. Adding to the challenge, a lab test was required to prove that the Swellpacker system design would meet operator internal approval before running it in the well.

The 13 5/8-in. Swellpacker system was delivered on time, and the required lab test report confirming that the packer could be safely run was provided several days before the operation was to begin. The Swellpacker system was then deployed and sealed successfully, exceeding operator expectations.

CHALLENGE

 Reliable secondary barrier zonal isolation in the event of severe losses during the cement job to avoid expensive remedial operations.

• Severe fluid losses anticipated;
• Well control due to huge volume of mud losses to formation and annulus pressure buildup;
• Packer OD of less than 14.65-in. after four days;
• Logistical obstacles to delivering the solution on time.

SOLUTION

Swellpacker systems with delay fusion layer to provide highly reliable secondary barrier to primary cement for zonal isolation.

RESULT

 Swellpacker systems provided effective zonal isolation control along with good shoe to drill ahead provided by cement, saving the operator money and optimizing logistics.

• 13 5/8-in. Swellpacker system was installed trouble-free;
• 10 days after the cement job and 14 days after the Swellpacker system passed the rotary table, the pressure in the C-annulus was at zero and no more pressure had built up.