Challenges and remedial measures of well drilling site development in Bangladesh

Abstract

Drilling activities can take place in diversified geological and geophysical settings, each posing unique type of challenge. There is no universal methodology to address all the situations. Therefore, each project is tailored on a case by case basis. However, it is possible to analyze the problems and to table the common items to bring them under a systematic procedure. Well site development is the initial stage of a drilling project. It involves mainly Civil Engineering works which includes earthworks, leveling, proper compaction, construction of rig and machinery foundation, well site yard, pipe rack, cat walk, mud pit, ware houses, deep water well with water line, office and personnel accommodation, security fencing/wall, sanitary and drainage works etc. An unplanned or faulty development of a drilling site may cause severe problems which may even jeopardize the entire drilling project. State-run and international oil companies have so far drilled about 186 wells in different geographical and geological conditions of Bangladesh. Currently, BAPEX and 4 IOC’s are conducting the country's drilling activities. In onshore, the North-Eastern territory of the country has offered the most of the oil and gas resources. Besides, a number of wells have been drilled in off shore as well. Despite of having the drilling experiences, it is difficult to get a generalized idea on the drilling issues due to lack of compilation of the individual experiences. In this study, the challenges and remedial measures of six representative well sites have been analyzed. This study took a closer look at the challenges and remedial measures of the sites as the first attempt of this kind in Bangladesh. It observed the nature of the problems and their reasons; degree of severity which causes time and cost overrun of a project. For example, the cost overrun comes from 5% to 44% and the time overrun comes from 0% to 83% in the same project due to the severity of the problems such as excessive rain, flood etc. It is revealed that, heavy rainfall during the monsoon and consequent flooding poses the biggest and most common problems for the pre-construction activities before drilling wells. The case-studies showed that the natural constrains caused delay in project implementation, difficulty of logistic movement, raise security issues, damage to equipments and cost overrun. The terrains are either low lands with seasonal water bodies, popularly known as haors, or hilly areas with dense forest. Both types of lands are susceptible to flooding, landslide or washout. Construction and maintaining of the approach road is the next biggest challenge, which is also tied to flooding and remoteness of the location. In some cases, scarcity of manpower and proximity to the international border are also problems. It is therefore important that the weather and flood pattern, availability of manpower and proximity to international border from locations should be taken into account to plan the logistic movement.