Coiled Tubing & Fluid Pumping | Schlumberger

Coiled Tubing and Fluid Pumping

CT applications for operations involving pumping a fluid into the well

CT cleanouts are used to remove debris and particulates from boreholes. Water- or oil-based fluids can be used and mixed with nitrogen if required. Most cleanouts are done with a simple BHA comprising a connector, a double check valve, and a wash nozzle. Wash nozzles are offered in different configurations, depending on the particular job and preference.

Other options for cleanout tools include

  • mandrel bypass tools when gas lift mandrels are included in the well completion
  • packer jumpers when encountering difficulties while passing through restrictions
  • positive displacement motors and bits.

Reverse circulation

In large casings with a restriction in the wellbore above, CT can be used for reverse circulation. A special surface rig-up is used switch the direction of flow simply by operating a few valves, and a safety pop-off valve is included to control the annulus pressure. 

Xtreme coiled services.

All coiled tubing services can be performed in high-pressure environments. Currently, well control equipment is available for working pressures up to 15,000 psi.

Xtreme coiled services.

Stimulation

CT is also used for acid stimulation. It can be placed across the perforated interval and reciprocated while the acid is pumped, placing the unspent and undiluted acid directly across the interval in question. Acid is not contaminated with borehole debris when it is placed though CT. Furthermore, live acid does not contact the wellbore, thereby protecting the production tubing and hardware. The well can be immediately returned to production after the stimulation operation by jetting it with nitrogen pumped through the CT. This reduces the chance of by-products precipitating as the acid is spent.

Cementing

During well abandoned or recompletion, CT can accurately place small volumes of cement inside the well as a balanced plug. Perforations can be squeezed and fluids can be pumped to dress off the top of a plug or clean out excess cement inside the well. Consequently, less preparatory work is required to recomplete the well. 

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