According to the observations in the outputs of PFE, the ability to detect the geological structures such as faults (gas chimney), folds (salt dome), and bright spots besides porosity estimation of sandstone reservoirs could be a guideline to select the drilling points.
Considering the peculiarity of the drill point configuration, a straightforward method for flank/flute intersection is derived.
Using this methodology, the generic definitions of the conventional angles on the drill point have been derived and presented.
Paradoxically, while this practice does limit delamination, the force exerted by the drill point is actually greater than in unsupported drilling.
The main cause of delamination is generally held to be the thrust force exerted by the drill point; the most commonly used method for reducing delamination is to place a support under the workpiece.
The present investigation is an attempt to study the effect of the cutting speed, the feed rate, and the drill point geometry on the residual tensile strength of the drilled unidirectional glass fiber reinforced epoxy composite using the Taguchi method and suggests the optimal conditions for maximum residual tensile strength.
The drill point was located at the first third of the dorsal iliac crest in sagittal section and 1 cm medial to the posterosuperior iliac spines in coronal section.
Furthermore, the Pb concentration was observed to decline with increasing distance away from the specific drilling point.
The flow network of the gas in the borehole and from each gas source is shown in Fig. 2, where point a is the drilling wellhead, point b is the junction of the borehole and the protected layer, point c is the gas drainage area boundary of the protected layer, point d is the drilling downhole, and point e is the gas drainage area boundary of the fissure zone.
