RiskVoyance - risk quantification for drilling operations

The well construction process is challenging as the goal is to satisfy several requirements; minimize well costs, obtain a usable hole/well and perform the operations in a safe manner. There are many sources to potential problems during the drilling process; geological uncertainty, equipment failures and human mistakes. Proper well planning is a key to a successful drilling operation. This project aims at developing a computerized prototype tool for predicting pressure-related problems during the drilling phase of well construction. The tool can be regarded as a probabilistic drilling simulator as it will evaluate the drilling process in terms of pressure control under a range of geological scenarios. The main goal of this project is to develop software that can be used for risk analysis and risk management in the well planning phase. Specifically, the tool will be used to a) Support decisions related to well design, b) Quantify risks related to pressure control, c) Establish a link between operational parameters and associated risks. The modelling framework (e.g. geological model, operations, managed pressure drilling) and software development are presently the main focus of the project. Specifically, and as presented in recently presented an d submitted papers, the key topics are: - Inclusion of uncertainties associated with reservoir inflow performance and choke operability. - Development of a framework for evaluating the ability to control the well pressure with uncertainty in the formation's pore, fracturing and collapse pressures.

The well construction process requires different skill sets; project management, risk analysis and technical and economic evaluation. The final well design parameters are usually the result of undertaking a three-step process: data sourcing, collation and analysis. In the analysis phase, well design parameters such as casing setting depths and mud weight are selected on the basis of assumptions on the subsurface environment that will be met during drilling. As of today, the selection of which subsurface e nvironments to use for dimensioning is done qualitatively, thus exploring a limited number of scenarios. What we propose here is a computerized tool for running a large number of "what-if" exercises, thus recording what may go wrong in the drilling proces s and which approaches that seem successful. With this approach, a well design can be evaluated under a variety of scenarios that are possible due to uncertainties related to geology, equipment and human performance, thus establishing a risk picture and o ptimizing selected parameters at the same time. The method that will be developed can be applied both to conventional drilling methods and to managed pressure drilling (MPD) methods. Focus will be on issues related to pressure control during drilling, as this is often the source to a variety of drilling problems. Relative to the planning process as of today, the drilling risk planning tool will provide a better systematization of uncertainties, a more formal framework for making technical decisions in li ght of the uncertainties, as well as provide an overview of risk factors and a basis for discussion on costs/benefits. The advantages of using the tool will be a more systematic planning and working process, reduced planning time and a larger degree of tr ansparency with respect to how technical decisions are made. Ultimately, the successful application of such a tool and methodology will improve drilling performance.