Analysis of stuck pipe incidents in Menengai

Abstract

Stuck pipe, or sticking, and lost circulation are the two main events which cause non-productive time (NPT) in the drilling industry. A considerable amount of time and resources can be spent in efforts to free a stuck pipe. Sometimes, stuck pipe events result in breakage (either intentional or non-intentional) of the drill string, leading to a lot of money being spent on fishing. Unsuccessful fishing operations have resulted in costly alternatives including side-tracking or, worse still, well abandonment. Stuck pipe situations are very common around the world with most data gathered in the petroleum drilling industry. A stuck pipe situation has led to abandonment of a well in the Menengai drilling field, Kenya, as of the date of writing this paper. This paper explores the stuck pipe problem in geothermal well drilling. The paper presents causes of stuck pipe events, predicting their occurrence, and common methods used to free a stuck pipe. There is also a review of methods used to back off stuck string and fishing. Finally, an analysis is made of stuck pipe events in a few wells drilled in Menengai, Kenya, using the graphical analysis software Easy View. The results are then discussed to identify the causes of stuck pipe in Menengai.