Coiled tubing tools

The completion tools that run on coiled tubing, and how to specify them

For completion and production engineers specifying a coiled-tubing-conveyed job: which tool classes suit coiled tubing, what to put in a quotation request, and where each option stops.

Maximus OIGA Private Limited manufactures the completion tools that are run and set on coiled tubing, built at the Manjusar/Savli plant in Vadodara, Gujarat, India. These are downhole well-completion equipment in the SpectraMax line, engineered to order and quoted against a purchase order.

This page covers coiled tubing tools from the completion side: which downhole tools coiled tubing conveys and sets into the completion string, which of them Maximus OIGA builds, how to specify one for a quotation, and the lead time to expect. Coiled tubing is one conveyance method among several, and the tool you choose depends on it.

Which downhole tools run on coiled tubing

Coiled tubing tools, the tools that run on coiled tubing, fall into three distinct groups. The surface spread runs and controls the string. The intervention bottom-hole assembly does mechanical work downhole, such as milling or fishing. The completion tools are the ones coiled tubing conveys and sets into the completion string, including bridge plugs, cement retainers and packers.

Coiled tubing is a conveyance method. It is a continuous steel string run into the well through an injector head, used to place and set tools where a jointed workstring or wireline is unsuitable. Wireline cannot push, and a workstring has to be made up connection by connection. Coiled tubing runs in one continuous length and can push, which is why it reaches places the other two cannot.

The surface spread is the equipment above the wellhead: the reel, the injector head and the pressure control equipment. Coiled tubing service and rental companies supply and operate it.

The intervention bottom-hole assembly is the working end for well intervention: connectors, a motor head assembly, jars, mills, agitators and downhole nozzles. This is thru-tubing intervention work, supplied by intervention specialists.

The completion tools are the downhole equipment that coiled tubing conveys and sets into the completion string: bridge plugs, cement retainers and packers. These are manufactured completion tools, and they are the group this page is about. Which of the three groups a supplier builds is the next thing to establish.

Which of these does Maximus OIGA Private Limited build

Maximus OIGA Private Limited manufactures the completion tools that coiled tubing sets, engineered to order under the SpectraMax brand and built at the Manjusar/Savli plant. That is the scope of what the manufacturer provides, and it tells you in one line whether this is the right supplier for your job.

Maximus OIGA builds the completion tools that a coiled-tubing-conveyed setting tool runs and sets. Under SpectraMax these families cover packer systems; cast iron products, which include bridge plugs and cement retainers; liner hangers; flow control; float equipment; and stage cementing. These are the tools that isolate a zone, control a squeeze, or hold in the completion string once coiled tubing has placed and set them, each built and validated at one plant and supplied engineered to order with its documentation.

The supply split on a coiled tubing job is clean. The completion tools come from the manufacturer, engineered to order and delivered by export against a purchase order with the documentation pack prepared for the market. The coiled tubing string, the surface spread, which includes the injector head and the pressure control equipment, and the job crew come from the coiled tubing service company. The tool specification is the part the operator controls, and it is the part this page helps you get right.

If you need a bridge plug, a cement retainer or a packer set on coiled tubing, this is the manufacturer to specify to. What coiled tubing conveyance changes about the tool itself is the next thing to understand, because it drives which tool you specify.

What changes when a completion tool is set on coiled tubing instead of wireline or a workstring

Coiled tubing conveyance changes the setting mechanism, the force available to set the tool, and how far into the well you can reach. So a completion tool set on coiled tubing is specified for the conveyance, not only for the well it goes into. This is standard coiled tubing mechanics, and you can check each point against your own well plan.

Reach. Coiled tubing can push. Wireline cannot, so in a deviated well or a horizontal section wireline needs a tractor or will not reach at all. A workstring can push but has to be made up connection by connection. Running on coiled tubing lets the setting tool reach into deviated and horizontal sections in one continuous run.

Well live or killed. Coiled tubing runs continuously through pressure control equipment, so the well can stay live while the tool goes in. Coiled tubing lets you work a live well without killing it first, and there is no connection-making time. A workstring run usually means killing the well before you start.

Setting force available. The setting force is where coiled tubing sets its own limit. The string has finite push before helical buckling and lock-up, so the force available to set a tool falls as the tool goes deeper and as the horizontal section gets longer. This is the constraint that decides whether a hydraulic setting tool or a mechanical setting tool is the right choice for the job.

Restriction and tool outside diameter. The tool has to pass the smallest restriction in the completion on its way to depth, and its setting mechanism has to work within the force and the flow the coiled tubing can deliver there. That is why the tool is matched to the conveyance and not picked on size alone. Differential sticking across a permeable zone is a further risk the running plan has to account for. With the conveyance understood, the next question is matching the tool class to the job.

Which completion tool suits which coiled tubing job

A completion tool for a coiled tubing job is chosen by the well condition and the outcome the job has to achieve, not by the product name.

Three SpectraMax families cover most coiled-tubing-set work: the bridge plug, the cement retainer and the packer. The outcomes they serve are zonal isolation, squeeze cementing, water shut-off and abandonment. What separates them is whether the isolation is permanent or has to be recovered, and whether fluid has to be pumped through the tool. Read the table on those two questions and the choice usually resolves itself.

The rule holds across all three rows: decide whether the isolation is permanent or must be recovered, and whether fluid is pumped through the tool, and the well condition points to one family. Once the tool class is settled, the next step is turning that choice into something a supplier can quote.

How do you specify a coiled-tubing-set plug, retainer or packer

To quote a coiled-tubing-set completion tool, a supplier needs six things: the casing or tubing it sets in, the smallest restriction it has to pass, the well deviation and depth, the well fluid and any sour service requirement, the setting method available on the job, and whether the tool has to be recovered.

Casing or tubing. Give the casing or tubing size, the casing weight and the casing grade the tool sets in. Weight and grade fix the drift diameter, and the tool has to seal against that exact inside diameter.

Restriction. State the smallest restriction the tool must pass on its way to setting depth. The tool outside diameter is chosen to clear it, so the drift is the number that matters here, not the nominal size.

Deviation and depth. Give the well deviation and the setting depth. Together with the horizontal length, these decide how much setting force the coiled tubing can deliver at the tool, which is what makes a setting method feasible or not.

Well fluid and sour service. Name the well fluid and state whether the service is sour. An H2S environment changes the material and the elastomer selection, and it is not something to leave to assumption.

Setting method. Say which setting tool is available on the job, hydraulic or mechanical. The completion tool has to match the setting tool the coiled tubing spread will run.

Recovery requirement. State whether the tool has to be recovered later or can be left permanent. This is the single question that most changes which tool you are quoting.

What drives the price of an engineered-to-order completion tool is the size and grade of the material, whether it has to meet sour service, the sealing and slip configuration, whether it has to be retrievable, and the quantity. Specify those and you get a quotation sized to the job rather than a general figure. Maximus OIGA Private Limited quotes against a well schematic or a specification sheet. Specifying the tool well also means knowing where each option stops.

Where does each option stop

Every coiled-tubing-set completion tool shares one limit: the setting force the coiled tubing can deliver at depth. That force falls as the horizontal section lengthens, and the string can reach helical buckling and lock-up before the tool reaches setting depth. When that happens, no tool in the table is the right answer until the running method is changed, and a tool left stuck can become a fishing job.

A permanent bridge plug stops being the right choice where the zone below has to be re-entered, because recovering a permanent plug means milling it out. If you expect to go back below it, a permanent plug is not suitable and you specify a retrievable tool instead.

A cement retainer stops being the right choice where no squeeze is intended. Its whole purpose is to control pumped cement, so on a job with no cement to place it is the wrong tool and not suitable for it.

A retrievable packer stops being the right choice where debris or scale may prevent its release. The recovery you are specifying it for is the thing most at risk, so on a dirty or scaled interval the retrievable feature can be exactly what fails.

Sour service is a further limit on every class. An H2S environment restricts the materials and elastomers that can be run, so a tool not specified for sour service is not suitable in one. Knowing where a tool stops is also what a supplier's records are for, which is the next thing to ask about.

What standards apply, and what should you ask any supplier to produce

You qualify a downhole completion tool supplier by the records it puts behind the tool, not by a slogan. Ask your supplier for these three records, and read each one for yourself. The same test holds for any supplier on your bid list.

• Qualification test report. The report for your exact model and size, tested to the recognized validation standard for packers and bridge plugs, ISO 14310. A validation grade belongs to the tool and size that was tested, not to a company, so it states what that tool is rated for and what it is not.
• Material and traceability records. The material test report for the body and the seals, heat traceability back to the material heat, and an inspection and test plan that shows which checks are witnessed and which are recorded before the tool ships.
• Documentation pack. The qualification test report, the material test report, the inspection and test plan and the heat traceability, gathered with the order and made part of the purchase order.

Maximus OIGA Private Limited prepares this documentation pack with the tool, so you can verify what you are buying rather than take it on trust. With the records covered, the remaining question for most buyers is supply time.

How long does a coiled-tubing-set completion tool take to supply

Lead time for a coiled-tubing-set completion tool from Maximus OIGA Private Limited runs in published bands by product class: 1 to 4 weeks, 4 to 12 weeks, and 8 to 16 weeks or more. Which band applies depends on the tool and the configuration, and the band is stated up front rather than left to the quotation.

What moves a tool from one band to the next is the size and grade of the material, whether it has to meet sour service, the quantity, and whether the configuration is a standard SpectraMax build or a new engineering release. A standard configuration in a common size sits at the short end. A new engineering release in a large size or a sour-service material sits at the long end, because it carries design and material lead time before anything is machined at the Manjusar/Savli plant.

These are tools engineered to order, not stock items pulled from a shelf, which is why the answer is a band tied to the work rather than a single number. Where a configuration is close to a standard build, the short band reflects that.

Publishing a lead time at all is uncommon in this market, so a buyer comparing options usually cannot get a supply answer without asking each supplier. A stated band is something you can plan a well program around. A few questions come up often enough to answer directly, which is where this page turns next.

Frequently Asked Questions 

What does Maximus OIGA Private Limited supply for a coiled tubing job?

The completion tools that coiled tubing sets: bridge plugs, cement retainers and packers, engineered to order with their documentation and a stated lead time. The supply split is clean, because the tool comes from the manufacturer while the coiled tubing string, the surface spread and the crew come from the coiled tubing service company. The tool specification is the part you control.

If we move a tool order away from a major service company, do we lose the integrated package?

Only if you were treating the tool and the job as one purchase. They are two. The tool, its documentation and its lead time are bought from a manufacturer. The coiled tubing string, the crew and the job execution are bought from a service provider. The two are contracted separately, and the tool specification is the part the operator controls. Whether to buy them together or apart is your call; the point is that they can be separated, and the tool is a specification you own either way.

Can a bridge plug set on coiled tubing be retrieved?

It depends on which tool was specified. A retrievable bridge plug is designed to be recovered; a permanent bridge plug is not, and recovering one means milling it out. It also depends on the well, because debris or scale across the interval can prevent a retrievable tool from releasing. Decide whether you will need to re-enter the zone below before you choose, because that decision sets the tool.

What do you need from us to quote?

Six things: the casing or tubing size, weight and grade; the smallest restriction the tool must pass; the well deviation and depth; the well fluid and any sour service requirement; the setting method available; and whether the tool has to be recovered. With those, you get a quotation sized to the job.

What records should we ask for before we buy?

Ask for the qualification test report for the exact model and size you intend to run, tested to ISO 14310, which tells you what the tool is rated for. Ask for the material test reports and heat traceability, and for the full documentation pack that travels with the order. Those records are how you verify what you are buying rather than take it on trust, and you can ask the same of any supplier.