RIASSUNTO
Abstract
Fishing operations are complex and time consuming. This is due to the associated uncertainty with the orientation and condition of the tool that requires fishing. In this paper, a case study is presented which demonstrates the usefulness of utilizing downhole camera technology in conjunction with fishing operations. The use of real time camera inspection enabled successful fishing of a challenging plug. In addition, the traditional trial and error approach used in most fishing operations was avoided reducing the operation time and cost.
The paper case study is a high pressure oil producer that has a stuck retrievable plug at 200 ft. The presence of the fish at a shallow depth makes well intervention operations critical from well control perspectives. In such cases, fishing operations must be meticulously designed to account and plan for contingencies should complications arise during fishing. Attempts to fish the plug using normal and heavy duty slickline were not successful. During these fishing attempts, several tools were lost in hole due to the damaged nature of the stuck plug adding to the complexity of the fishing operation.
To address this challenge, a downhole camera with real time data transmission capability was run in the well using coiled tubing to enable viewing the condition and orientation of the lost fishing tools and the stuck plug. The results of the camera inspection runs were instrumental in subsequent fishing tools selection and adjusting the operating procedures. The first camera run revealed the presence of metal objects obstructing proper latch to the fish neck. Following clean-up runs with magnet, the second camera inspection run clearly showed partial damage to the top of fish neck (chipped out metal piece). The rest of the fishneck was found intact.
Given the nature of damage to the top of the fishneck, conventional fishing tool sizes (3 in.) were not able to latch the fish. Accordingly, a smaller fishing tool (1.26 in. spear) was run and latched inside the bottom of the fish neck instead of the damaged top. The 1.26 in. spear run was successful in latching inside the fishneck and in recovering the fish safely. The fishing operation design, job execution, and contingencies will all be discussed in this paper.