What is the best way to design a drilling fluid program that meets well objectives and minimizes risk?

1 Define well objectives

The first step is to define the well objectives, which are the specific goals and requirements of the drilling operation. These may include the target depth, location, and orientation of the well, the desired production rate and quality, the safety and environmental standards, and the budget and schedule. The well objectives will guide the selection and evaluation of the drilling fluid properties and parameters, such as density, viscosity, rheology, filtration, chemical composition, and compatibility.

2 Assess formation characteristics

The second step is to assess the formation characteristics, which are the physical and chemical properties of the rock layers that the well will penetrate. These may include the porosity, permeability, pressure, temperature, salinity, hardness, and reactivity of the formation. The formation characteristics will influence the type and performance of the drilling fluid, as well as the potential drilling problems, such as lost circulation, wellbore instability, stuck pipe, formation damage, and corrosion.

3 Identify drilling challenges

The third step is to identify the drilling challenges, which are the technical and operational difficulties that may arise during the drilling process. These may include the directional control, hole cleaning, torque and drag, hydraulics, bit wear, borehole enlargement, and well control. The drilling challenges will affect the design and optimization of the drilling fluid system, as well as the selection and application of the drilling fluid additives, such as weight materials, viscosifiers, thinners, filtrate reducers, and inhibitors.

4 Choose drilling fluid type

The fourth step is to choose the drilling fluid type, which is the base fluid and the main components of the drilling fluid. There are three main types of drilling fluids: water-based muds (WBM), oil-based muds (OBM), and synthetic-based muds (SBM). Each type has its own advantages and disadvantages, depending on the well objectives, formation characteristics, and drilling challenges. For example, WBM are cheaper and more environmentally friendly than OBM and SBM, but they may cause more formation damage and wellbore instability in reactive shales.

6 Optimize drilling fluid program

The sixth step is to optimize the drilling fluid program, which is the process of adjusting and improving the drilling fluid system to achieve the best results and performance. This involves modifying and updating the drilling fluid properties and parameters, such as density, viscosity, rheology, filtration, chemical composition, and compatibility, based on the well objectives, formation characteristics, and drilling challenges. The optimization also includes implementing and reviewing the best practices and guidelines, such as the mud program, the mud engineering, and the mud disposal, to ensure the quality and efficiency of the drilling fluid operation.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?