TY - THES

T1 - Integrated Approach to Evaluate the Drilling Solutions for Downhole Drilling Problems

AU - Stulec, Martin

N1 - embargoed until null

PY - 2020

Y1 - 2020

N2 - The role of oil and gas in the modern world is still very important. As the crude oil price is at low level, there is a constant need to improve drilling efficiency and to reduce drilling costs to the minimum. In order to do so, drilling efficiency needs to be improved. The best way to improve drilling efficiency is to evaluate different drilling methods. The main objective of this thesis is to develop the evaluation decision-making process in evaluating preventive barriers for the downhole drilling problems. There are various solutions available at the market. One of the evaluation tools used for deciding which method would be the most cost efficient is weighted matrix method. However, this method has some limitations, as there are a lot of assumptions and uncertainties associated with the input parameters. Therefore, in order to enhance the evaluation of the decision-making process, another evaluation tool was presented. That is the probability of success method. Afterwards, these two tools were combined into an integrated approach. This was done in order to evaluate the preventive barriers for downhole drilling problems in the best possible way. To test these developed methods in a real situation, a case study was performed to validate the approach. The main objective of a case study was an investigation of drilling operations in re-entry drilling for W-1 JR well on F-1 field. Based on drilling reports NPT (Non-Productive Time) was extracted and root causes were established. After calculating the NPT, three main problems surfaced: bit balling, high torque and drag and stuck pipe. For dealing with these problems, different methods are proposed to reduce or to mitigate encountered drilling problems in following re-entry campaign in that field area. To evaluate proposed drilling methods, an integrated approach was used, which determined that the best solution for bit balling is to change drilling hydraulics. On the other hand, the best solution for the high torque and drag and stuck pipe would be rotary steerable system.

AB - The role of oil and gas in the modern world is still very important. As the crude oil price is at low level, there is a constant need to improve drilling efficiency and to reduce drilling costs to the minimum. In order to do so, drilling efficiency needs to be improved. The best way to improve drilling efficiency is to evaluate different drilling methods. The main objective of this thesis is to develop the evaluation decision-making process in evaluating preventive barriers for the downhole drilling problems. There are various solutions available at the market. One of the evaluation tools used for deciding which method would be the most cost efficient is weighted matrix method. However, this method has some limitations, as there are a lot of assumptions and uncertainties associated with the input parameters. Therefore, in order to enhance the evaluation of the decision-making process, another evaluation tool was presented. That is the probability of success method. Afterwards, these two tools were combined into an integrated approach. This was done in order to evaluate the preventive barriers for downhole drilling problems in the best possible way. To test these developed methods in a real situation, a case study was performed to validate the approach. The main objective of a case study was an investigation of drilling operations in re-entry drilling for W-1 JR well on F-1 field. Based on drilling reports NPT (Non-Productive Time) was extracted and root causes were established. After calculating the NPT, three main problems surfaced: bit balling, high torque and drag and stuck pipe. For dealing with these problems, different methods are proposed to reduce or to mitigate encountered drilling problems in following re-entry campaign in that field area. To evaluate proposed drilling methods, an integrated approach was used, which determined that the best solution for bit balling is to change drilling hydraulics. On the other hand, the best solution for the high torque and drag and stuck pipe would be rotary steerable system.

KW - NPT/ Evaluierungs-Entscheidungsprozess/ Gewichtete Matrix-Methode/ Erfolgswahrscheinlichkeits-Methode/ Integrierter Ansatz/ Bit-Balling/ Hohes Drehmoment und Widerstand/ Gestecktes Bohrroh

KW - NPT/ Evaluation Decision-Making Process/ Weighted Matrix Method/ Probability of Success Method/ Integrated Approach/ Bit Balling/ High Torque and Drag/ Stuck Pipe

M3 - Master's Thesis

ER -