This paper describes a variety of Coiled Tubing perforating approaches and techniques which have been evaluated, planned and implemented during the development of the Cusiana and Cupiagua Fields. A synopsis has also been prepared which outlines the advantages/disadvantages of each of these approaches. In addition, several detailed case-histories are included which provide the actual Operating characteristics of each approach. The particular operational advantages, of Coiled Tubing Perforating, for Cusiana and Cupiagua have also been summarized. These include, the long intervals, deep wells, complex well trajectories, large gun-size, pre-frac requirements and poorly understood pore-pressures. An assessment has also been made of the additional benefits, IOR, cost savings, etc. that these techniques have potentially provided. Finally, there is some discussion as to the future direction of Coiled Tubing perforating for the Cusiana and Cupiagua Fields. Issues include a clearer definition of the Opportunities/Requirements and the additional Techniques/Systems which will be necessary to allow these to be realized. Introduction During the development of the Cusiana and Cupiagua Fields; customized charges were designed specifically for these non-homogeneous Quartz-Arenite formations. These resulted in a measurable productivity improvement, however the overall perforating efficiency remained low. As a better understanding of the mechanisms involved was acquired, it became clear that one of the primary factors affecting the perforating efficiency was the magnitude of the under-balance achieved. From the available data, it could be seen that this parameter had a considerable impact on the initial productivity or injectivity. Perforating operations utilizing electric-line are typically limited as to the absolute magnitude of under-balance at which they can safely operate. In addition tortuous, side-tracked and deep well trajectories can create excessive drag-forces, which cause operational problems and result in forces close to the operational limitations of the cable. In recent Years Coiled Tubing conveyed perforating has proven to be an excellent alternative to electric-line; in terms of achieving substantially higher values of underbalance and when attempting to access deep and highly deviated wells where dog leg severity may be a concern. Background Two major oil fields under development in the Casanare Region of Colombia are the Cusiana and Cupiagua Fields. The Cusiana and Cupiagua Fields are located in the foothills on the Eastern side of the Eastern Cordillera of the Andes mountain range. The current tectonic environment is characterized by active thrust faulting towards the South-East, the direction of maximum horizontal stress1. Reservoir bed dipping can be severe, this generally results in the wells following a natural walk, while being drilled, towards the preferred azimuth of fracture propagation.

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractThis paper describes a variety of Coiled Tubing perforating approaches and techniques which have been evaluated, planned and implemented during the development of the Cusiana and Cupiagua Fields. A synopsis has also been prepared which outlines the advantages/dis-advantages of each of these approaches. In addition, several detailed casehistories are included which provide the actual Operating characteristics of each approach.