Fishing operations

Bottom hole assemblies and certain types of downhole equipment (e.g. logging tools, MWD tools) cost several US 100,000. Some logging tools will have radioactive sources which may need to be recovered or isolated for safety and legal reasons. However, prior to commencing fishing operations, a cost - benefit assessment will have to be made to establish that the time and equipment attributable to the fishing job is justified by the value of the fish or the cost of sidetracking the hole. 

The drill pipe itself can be used for formation evaluation (Drill Stem Testing— DST), well stimulation (fracturing, acidizing), and fishing operations. 

To avoid costly fishing operations, loss of material and time, the drill pipe must be carefully inspected according to the following procedure [30] ... 

There are a number of causes for fishing operations. Many of the causes are preventable by careful planning of the drilling operation and being very watchful for the indication of possible future trouble [149]. 

Ajar is a device for providing an impact load to the fish when the fish cannot be retrieved by normal string and derrick forces. There are purely mechanical jars and hydraulic Jars (see the section titled Drilling Bits and Downhole Tools for details on drilling Jars). In a fishing operation the Jar is usually placed... 

The inside diameter of 9 -in., 53.50-lb/ft casing is 8.535 in. (see Section titled Fishing Operations ). The internal capacity per unit length of casing is... 

By any standard of measure, corrosion is a severe and costly problem in the drilling industry. Corrosion costs the oilfield millions of dollars each year, and a large portion of this expense is due to the replacement of steel goods. Other expenses include lost drilling time due to equipment repairs, fishing operations, and extra trips caused by corrosion-related failures. 

Unlike merchant ships, the maneuverability of fishing boats is limited while fishing operation, and speed is frequently increased and decreased. Fishing boats are propelled at low speed when using dragnets the relationship with AIS, which is automatically determined by the transmission interval according to her speed, is therefore particularly important in this case. 

The number of vessels suffering weather damage is comparatively low as seen in the graph in Figure 2.5. Small vessels are particularly vulnerable to these accidents, especially when they go out further away from the coastline for their fishing operation (due to the reduced fishing opportunities in British waters). These small vessels will be working far offshore where they cannot withstand the severe weather and wave conditions that can occur unexpectedly. Heavy... 

The purpose of this analysis is to address the high level of human errors that occur during the fishing operation on board fishing vessels. As an example, the initial shooting operation of the fishing nets is considered. 

---