PrintIn addition to the operating company and the drilling company, specialized companies, called Service Companies, provide specific well services at the rig-site during certain operations. The service company personnel also form an integral part of the well drilling team.
- Drilling Fluids Engineer or “Mud Man”:
The Drilling Fluids Engineer (often referred to as “a Mud Man”) is a wellsite specialist who ensures that the properties of the Drilling Fluid (often referred to as “Mud”) meet the specifications for the section of the wellbore that is currently being drilled. As the well depth increases, the specifications of the drilling fluid will change as the rock and fluid properties encountered by the well change. The drilling fluids engineer ensures that (1) the Mud Pumps are operating properly, (2) any drilling fluid additives are onsite and are capable of achieving the specifications required by the current and future sections of the wellbore, and (3) all additives are added at the appropriate times (or, if required, the mud is switched out entirely) when well conditions change. The term “mud” is used in oil and gas well drilling because historically the most common water-based drilling fluids were mixtures of water and finely ground, bentonite clays which, in fact, are muds. - Cement Engineer:
The Cement Engineer is a wellsite specialist who ensures that (1) the Cement Pumps are operating properly, (2) cementing operations are performed in a safe manner and are capable of achieving the cementing objectives of the well, (3) the cement properties (rheology, fluid loss, slurry thickening time, slurry setting time, etc.) meet the specifications required for the cementing operation, and (4) cement additives are onsite and can achieve the desired cement properties. During the oil and gas well drilling, Casing must be cemented into place to protect the environment from the wellbore (and to protect the wellbore from the environment). Casing is steel pipe used to isolate the environment from the wellbore and from the drilling operations. During cementing operations, a cement slurry is pumped downward through the interior of the casing and then upward through the annular space between the wellbore and the outer diameter (O.D.) of the casing. The cement is then allowed to set in this annular space. - Logging Engineer:
As discussed earlier, Well Logs or Open-Hole Logs are run periodically during drilling operations (prior to the setting of casing – most importantly over the producing intervals prior to the installation of the production casing string or liner). Well logs are records from measuring devices that are used to evaluate certain properties of the downhole rocks. The logging engineers make sure that all logging equipment is working properly and that all logging tools are accurately calibrated. Typical processes logs measure reservoir properties such as porosity, fluid saturations, and permeability (after calibration with well logs or well tests). - Well Test Engineer (Optional):
Once a well has reached its target formation(s), it may be tested with a Drill Stem Test (DST). In a drill stem test, the formation of interest is isolated using a temporary completion, and fluids are produced through the drill pipe or a DST string. The well is flowed at a predetermined rate-time schedule to estimate reservoir characteristics such as reservoir pressure, reservoir permeability, and anticipated production rates. The main objective of a DST is to determine whether the well is economically viable and warrants a permanent completion or whether the well should be Plugged and Abandoned (P&A’ed). Drill stem tests are typically run on Exploration Wells or Appraisal Wells where reservoir properties may not be fully understood. In Development Wells in reservoirs with known property ranges and property trends, DSTs may not be required to determine whether a well should be completed or not, and that decision can be made from open-hole logs. - Well Completions and Stimulation Engineers:
Once a well has reached its target formation(s) and the decision to complete the well has been made, the well is completed and stimulated (not all wells are stimulated). As we discussed in earlier lessons, stimulation refers to the process of Acidizing or Hydraulically Fracturing (Frac’ing) the well in order to improve the flow conditions near the well. Due to the controversies associated with the hydraulic fracturing process, you may have seen photos or videos of wells being hydraulically fractured in the news or on the Internet. The completions and stimulation engineers coordinate the completions operations with the tool pusher and company man, ensure that the completion or stimulation process meets the objectives of the well, and supervise the crews performing the work. Typically the role of a completions engineer is assigned to a production engineer.