The technology for coiled-tubing-conveyed perforating (CTCP) under extreme conditions has been available for a number of years, but until recently, the techniques have not been used in Venezuela. This paper will describe the first experiences in which CTCP has been used in this area.

The first candidate identified for the application was a new well in East Venezuela. This well was the first high pressure, high temperature (HP/HT) highly deviated deep monobore well completed in El Furrial Field in the North Monagas area that was perforated underbalanced with this technology. Although several traditional perforating methods were initially evaluated, the decision was made to perform the operation underbalanced using rig-assisted coiled-tubing technology because of the following advantages that could be realized from use of this method:

  • Debris in the tunnel would be reduced, minimizing the potential for formation damage.

  • The debris could be circulated out more easily.

  • The use of kill fluid to control the well would not be necessary.

  • By eliminating the cost of the kill fluid and the resulting costs of handling the returned kill fluid, well costs would be reduced.

The operation was performed in a live well with a 77-degree maximum well deviation and total depth (TD) of 17,907 feet.

Several engineering simulations were performed before the job. These simulations enabled the operator and service engineering personnel to quantify the effects of CT fatigue, lockup, stresses, forces, elongation due to weight and temperature, and buoyancy effects. Other important factors considered were safety, health, environment, quality and well control, taking into account all possible contingencies. Finally, nine (9) coiled tubing runs were performed to complete the well, a total of 1,190 ft of 3 3/8-in., 6 shots per foot (SPF) and 2 ¾-in., 6 SPF guns were run. In all of the coiled-tubing-conveyed perforating runs, the expended guns were retrieved successfully under live well conditions. To retrieve the guns without killing the well, a subsurface flapper-type safety valve, which enabled the operations to be performed under controlled conditions, was used.

Currently, the well is producing 19,621 BOPD through a 1-in. choke and 1,591 psi surface pressure.

Production and wellhead pressure expectations for this well were exceeded.

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