International Journal of Advances in Scientific Research and Engineering (ijasre) E-ISSN : 2454-8006 DOI: http://dx.doi.org/10.7324/IJASRE.2018.32591 Volume 4, Issue 1 January-2018 www.ijasre.net Page 103 Formulating Drilling Mud for Troubled Zone Formation Using Locally Sourced Materials Oloro John. Senior Lecturer Petroleum and Gas Engineering Department Delta State University Abraka, Delta State Nigeria _______________________________________________________________________________________ ABSTRACT This paper is to formulate locally drilling mud that will be used to drill trouble zones formations successfully. Trouble zones are zones with abnormal characteristics encountered during drilling operations, such as zones of high circulation lost and zones with high formation pressure. In this paper, the zone of abnormal lost circulation was considered. For drilling to be successful drilling mud was formulated and beneficiated to lessen its filtrate into the formation and also raise its density. The outcome of this research work shows that mud formulated and beneficiated with local clay and bentonite had a decrease of filtrate volume (in percentage (%)) into the formation from 22.3 to 7.8 and 5.6 to 5 respectively. The outcome of mud density after beneficiated with 70g of barite and subjecting it to temperatures up to 80°C was still very high (12.6ppg for local clay and 13.4ppg for bentonite). Since local materials used here had close results in cumulative filtrate loss and mud density, they can make use instead of foreign materials so as to save more resources that are spent on importation. Keywords: Drilling, Fluid, Additive, Filtration, Formation. ______________________________________________________________________________________________ 1. INTRODUCTION Drilling fluids serve many purposes in a drilling process. These include, the elimination of cuttings, lubricating and cooling the drill bits, supporting the stability of the hole and preventing the inflow-outflow of fluids between well and the formation [1].To formulate a drilling mud to handle trouble conditions, drilling test , drilling process and study of the formation has to be done to determine the effectiveness of the drilling mud[2]. Trouble zones considered in this paper was zone of high lost circulation. For drilling to be successful, drilling mud has to be formulated and beneficiated to reduce its filtrate into the formation and also raise its density[3]. 2. FILTRATION PROPERTY OF DRILLING MUDS Filtration is the process whereby of the liquid phase of the drilling mud pass through a permeable formation by differential pressure. During this process, the insoluble particles are separated from the filtrate, forming a filter cake. The knowledge of this process is very important in the design of drilling fluid formulation. Filtration across the cake depends on several properties such as