Results to date are compared with previous performance in the Gulf of Thailand (GoT). The purpose of this paper is to demonstrate how inaccuracy in standard directional-surveying methods affects wellbore position and to recommend practices to improve surveying accuracy for greater confidence in lateral spacing. Wellbore position is computed from survey measurements taken by a measurement-while-drilling (MWD) tool in the bottomhole assembly (BHA).
Results to date are compared with previous performance in the Gulf of Thailand (GoT). Reservoirs consisting of heterogeneous carbonates and shaly sands pose formation evaluation challenges for conventional logging-while-drilling (LWD) measurements. Magnetic resonance techniques hold promise for improving understanding of these reservoirs. This paper discusses ultradeep directional-resistivity (DDR) logging-while-drilling (LWD) measurements for high-angle and horizontal wells that have been applied recently with success on the Norwegian continental shelf (NCS).
PTTEP to Buy Murphy Oil’s Malaysian Business for $2.1 Billion Thailand’s PTTEP is doubling down on Malaysian oil and gas in an effort to broaden its reach in its native Southeast Asia. Results to date are compared with previous performance in the Gulf of Thailand (GoT). A new measurement-while-drilling (MWD) tool has been designed that can operate reliably at 200°C and 207 MPa, providing real-time direction and inclination surveys, azimuthal gamma ray, annular and internal pressure while drilling, and shock and vibration measurements.
When the joint development of extreme-high-temperature tools began in May 2014, the goal of the collaboration was to eliminate wireline in wells with temperatures over 175°C. Historically, the need for wireline was driven by the requirement to identify hydrocarbons, measure reservoir properties, and book reserves in high-temperature wells; this was accomplished by using a wireline string consisting of gamma ray (GR), resistivity, formation-density, and neutron-porosity sensors. Because of the 175°C temperature limits of the available LWD technology at that time, there was no viable option to log these wells while drilling. This resulted in valuable rig time spent on additional trips to change out bottomhole assemblies (BHAs), mitigate temperatures, and run wireline to gather this data. This also increased the exposure to nonproductive-time (NPT) events, stuck wireline tools, or loss of data if these tools did not reach bottom. Thus, the requirement arose to log these wells while drilling to reduce days per well and improve data collection. To this end, the joint development of extreme-temperature LWD tools was initiated and staged in two phases.
The technology can rotate independently from the casing when encountering obstructions and hanging. The rotation is performed by reciprocating the casing through 3- to 5-ft strokes that cause the tool shoe to act as a bit and ream. It drills off the obstruction and guides the casing string through ledges, tight swollen sections, and doglegs, allowing effective removal of fill and debris from below the casing/liner shoe to land at the intended total depth (TD).