Downhole drilling motors or mud motors are frequently used during the oil and gas well construction, especially for construction of directional and horizontal segments. However, low operation life of the down hole drilling motors and high rate of wear in their working elements may constrain their application due to technical and economical disadvantageousness. In this work, a high-torque modula...

Article presents results of study on possibility of increasing the efficiency of drilling directional straight sections of wells using screw downhole motors (SDM) with a combined method of drilling with rotation of drilling string (DS). Goal is to ensure steady-state operation of SDM with simultaneous rotation of DS by reducing the amplitude of oscillations with adjusting the parameters of dril...

This paper proposes the use of a hybrid approach to perform the trajectory control in the oil drilling industry using Rotary Steerable Systems (RSS). Two levels of automation are proposed, the attitude control (Level 1) regulating inclination and azimuth downhole and the outer loop (Level 2), that monitors the performance of the inner loop and controls the directional drilling commands issued t...

Feasibility of drilling with supercritical carbon dioxide to serve the needs of deep underbalanced drilling operations has been analyzed. A case study involving underbalanced drilling to access a depleted gas reservoir is used to illustrate the need for such a research. For this well, nitrogen was initially considered as the drilling fluid. Dry nitrogen, due to its low density, was unable to ge...

For complex drilling operations with narrow geo-pressure windows, it is not uncommon to have problems with formation fracturing, due to erroneous mud pump management. To assist the driller in managing the circulation, it is possible to limit both the acceleration of the mud pumps whilst changing the flow-rate as well as the actual flow-rate, to avoid generating downhole pressure above the fract...

Executive summary This thesis proposes and evaluates a concept for downhole depth estimation by matching subsurface measurements from two sensors in a bottom hole assembly. The application of a downhole depth estimate in automated subsurface navigation has also been demonstrated. One of the key hurdles in achieving real time subsurface navigation lies in communication bottom neck between surfac...

The Cajon Pass Scientific Drilling Project is a broad, interdisciplinary experiment involving over two dozen principal scientists. Phase I of drilling, coring and downhole experimentation began Dec. 8, 1986 and ended Apri12, 1987 with the hole at a depth of 2115 m, 82 m of core recovered and a wide range of downhole experiments successfully completed. In this paper we briefly outline the scient...

– World wide drilling is developing for oil, gas or water resources. Electric motors power 75% of the total drilling rigs installation, augmenting to 95% for the case of Romania. Monitoring diesel generators micro-power station and motors of the rig is the second important thing to do and complete the main task of drilling process monitoring. This paper describe a monitoring and control system ...