stylistic:style_transfer, linguistic:translation, structural:expansion, linguistic:paraphrasing
Planning

The target (the endpoint of the well) will be matched with a surface location (the starting point of the well), and a trajectory between the two will be designed. There are many considerations to take into account when designing the trajectory such as the clearance from any nearby wells (anti-collision) or future wellpaths.

Before a well is drilled, a geologic target is identified by a geologist or geophysicist to meet the objectives of the well. When the well path is identified, a team of geoscientists and engineers will develop a set of presumed characteristics of the subsurface path that will be drilled through to reach the target. These properties may include lithology pore pressure, fracture gradient, wellbore stability, porosity and permeability. These assumptions are used by a well engineering team designing the casing and completion programs for the well. Also considered in the detailed planning are selection of the drill bits, Bottom hole assembly, and the drilling fluid Step-by-step procedures are written to provide guidelines for executing the well in a safe and cost-efficient manner.

With the interplay with many of the elements in a well's design, trajectories and designs often go through several iterations before the plan is finalized.