The majority of the fields in the Gulf of Thailand can be classified as small lateral gas pockets in which the combinations of complex structural and stratigraphic traps form the primary geological closure. Commingled production from multilayer reservoirs and a strategic development plan should enable a successful, viable project. These objectives will pose challenges to drilling operations because they require major expenditures. Because of limited resources, such as recoverable reserves, budget, manpower, and technology availability, pre-well planning is vital. Generally, the well trajectory design is directly controlled by many factors. The most influential of these factors include prospects, infrastructure, tectonic structure, and well proximity. One of the challenges in the past has been the well trajectory, which was determined by both geosciences and drilling engineers. For example, numerous iterations and discussions between both parties result in the identification of subsurface and engineering constraints, including drilling parameters, hazards, seismic anomalies, faults, and well spacing. This paper focuses on the integration of those concerns by using integrated well planning software to improve workflow processes and manpower and, ultimately, to optimize asset value. The process will begin with data gathering, optimizing the platform location, performing target selection/target picking, determining the well trajectories, and creating the drilling plan. As a result, drilling concerns will be mitigated at the beginning of the well planning stage through the collaboration of the team members. The objective of this work is to enable the well to penetrate the planned targets in a controlled manner and with a safe operation, thereby minimizing drilling costs.