Unconventional Radioactive Source Retrieval Inside LWD in Horizontal Well

Abstract

Horizontal drilling is one of development strategies to optimize the oil recovery, especially in a mature field. Horizontal well can reduce water and gas coning and prevent the pressure drop around the well bore, therefore the oil recovery can be increased.Radioactive source in Logging While Drilling (LWD) tools is used for X-42 horizontal drilling well but stuck problem that occurs during the drilling operation can be caused by differential sticking or failure hole cleaning. High angle inclination in horizontal well certainly increases the difficulty of retrieval job.As a company regulation, the radioactive source should be retrieved before continuing the efforts to free the drill string. The wireline has agreed to help the radioactive retrieval but this operation should be done in 81°of inclination. Then, it will need a thrusting force to facilitate the bottomward movement of the assembly. Two attempts of retrieval with wireline are made before they bring up the idea of using sucker rod as the replacement a wireline cable. This paper explains how the unconventional radioactive retrieval method with sucker rod as the alternative of wireline is more reliable to retrieve the radioactive fish especially in horizontal wellbore which technically has a very high inclination and 3D profile which the tool need a thrusting force to push the fishing tool assembly to the bottom.