Directional Drilling - Advanced Trajectory Modelling
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SummaryDrilling operations are a significant cost in the process of recovering hydrocarbons. The operations are advanced and associated with large HSE and financial risks. The main objectives in a successful drilling operation are to construct safe and economically efficient wells, but the success also depends on hitting the target. As the drilling operation has very high standards of execution, a good drilling operation depends on a good well plan. The planning phase is a large and complex process as it engineers all aspects of a drilling operation. This is key to create safe and economically efficient wells. Well trajectory planning is a mixture of many parameters but in the end it comes down to identifying the most optimum well path. That means they should be based on exact mathematical calculation models, to precisely calculate well bore trajectories. The industry uses a number of different planning tools that makes it possible to calculate and plan complex well path trajectories. Very few studies have addressed this topic in a systematic manner.In this thesis, a large study has been made on the background of well planning and the well planning software s used in the industry today. The industry leader within well planning software is Halliburton Landmark s Compass. Compass has been used as a base study in this thesis. Work presented, has looked at three essential parts of the well planning software.1. The Software Model2. The Calculation Models3. The FunctionsThe main objective of this thesis has been to identify the different calculation models used in these programs and to program suitable functions similar to those found in existing planning softwares, in an attempt to create a new and more user friendly well planning software. Also, there is not much in the literature or information supporting what the different software models do to create well paths so a better understanding of the engineering of 3D well paths has been developed. A study was done to find/map different calculation methods that develop precise wellbore coordinates. A number of calculation models were found, but the bulk of these models is presented as models that are used to calculate already drilled wells. However, two new methods were identified. The method called Exact departures, Constant Turn Rate Method was found to give accurate results and is also the main calculation model found in the well planning softwares. This is the main calculation model used to support the functions presented in this thesis. The major part of the work presented in this thesis relates to the construction of precise and user friendly functions, that allow calculation of exact well paths. Using Compass as an offset to calibrate the programmed models, a substantial study has been done to understand and identify assumptions and how the presented functions work in Compass. The result is accurate program functions. The results show exact and accurate calculations - identical to compass. This thesis also presents the basics behind the operational phase, including surveying and anti-collision. Some work is left for further investigation. In the process of constructing a new well planning tool, a software or platform has to be programed to implement the functions presented in this thesis. Some of the functions presented also have some limitations that have to be finalized. Furthermore, more functions have to be developed, and programing of a plotting tool is also left for further work.