Drilling Manpower Planning: Using a Systems Dynamics Approach

Abstract

SPE Members Abstract This paper summarizes the results of a study testing the idea that "System Dynamics" techniques can be applied to gauging the effects of manpower application on drilling performance. The techniques discussed here are traditional engineering modelling techniques that have lately been applied to management and petroleum problems, and hold promise of broad applicability in drilling management. The specific problem of manpower planning was chosen as a test case for other drilling applications. The concept behind these techniques is to quantity the behavior of the system describing the specific problem at hand. In this way, the consequences of assumptions about a process are explicitly tested. The manpower planning model described here is the result of an iterative process, whereby the model's basic form and predictions were compared with actual results. The scope, purpose, and benefits are described on the following pages. The study showed that System Dynamics techniques are useful tools for planning drilling manpower requirements. Introduction Because they now need to more closely monitor accountability, profit, competitiveness and client satisfaction, many oil company drilling organizations are more rigorously attempting to quantity performance. Since a drilling organization's primary resource is manpower, this study was undertaken to determine R System Dynamics (SD) techniques could help distribute this resource more efficiently. A second, and possibly more important, justification for this study was to develop a way to quantity the effectiveness of drilling manpower. There has long been debate both inside and outside of many drilling organizations about the most cost effective way to utilize drilling manpower. This study develops a method by which the appropriate level and type of drilling manpower can be determined over time. DRILLING MANPOWER MODEL The basic finding of this study is that drilling manpower requirements can be more efficiently gauged using the SD model described here. This model combines budget information and a series of relationships describing the manpower required in each phase of a drilling operation to allocate manpower most cost effectively to achieve project goals. The model can be used to improve operations four ways. First, it can be used to plan manpower requirements for each business unit, either yearly or several months in advance. Used this way, the model can help local management allocate drilling manpower between projects so as to achieve minimum drilling costs. Second, to minimize total cost to the corporation, the model can be used as a coordination tool to aggregate and compare each business units' manpower requirements and to allocate drilling manpower between units. Third, the model is effective for determining the corporation's total drilling manpower requirements and the appropriate mix of consulting personnel. Finally, by comparing the model's predictions with actual performance data, its basic assumptions can be verified over time. This is one of the model's most important features. Figure 1 outlines the manpower planning SD model's basic idea. The amount of work required to property plan, implement, and evaluate drilling operations is assumed to be a function of the number and type of different wells to be drilled and the workload required to achieve client performance goals. The work required for a specific well type is broken into three phases: pre spud work, operational coverage, and close down work. The model tracks how many wells are in each phase and then calculates the amount of prespud, operational coverage, and close down work required, depending on a well's type. The model is simply a mathematical scheme that tracks the progress of a series of wells through the approval, drilling and close down phases and then specifies the amount of work required (as a function of time) to property drill that series of wells. The number of a particular type of well entering the process depends on how the budget is allocated over time. (NOTE: The symbols in Figure 1 have specific mathematical meanings in the SD discipline.) To use the model, a drilling organization typically defines four to six well types that represent the range of drilling found in a particular business unit. Each different well type should represent wells that require similar resources (time, cost and manpower) to drill efficiently to achieve the mutually agreed upon performance goals. Different well types each require different amounts (man weeks), and kinds (engineering, foremen, technical, etc.) of work, different times to drill, and different prespud and close down times. Given definitions of these differences, the model then specifies the amount of work that should be necessary to properly drill these various types of wells within a given budget. An important feature of the model is that it does not provide a lump manpower estimate, but rather that it continually estimates manpower requirements over time. P. 131^