WorldWide Drilling Resource

Using Subsurface DNA in the Oil Industry Adapted from Information by Biota Biota uses DNA sequencing and data science applications to explore the earth’s subsurface, which provides insights to the oil industry for maximizing reservoir production and reducing environmental impact. With DNA data services, Biota can supply information for production profiling, sweet spot identification, well spacing, oil potential, and reservoir connectivity. Subsurface DNA Diagnostics™ was recently used in the Wolfcamp Shale in Texas to estimate vertical drainage heights and landing zones for multiple laterals wells. The results provide groundbreaking reservoir insights, which will help optimize well spacing and production monitoring. Subsurface DNA was also used to mon- itor well-to-well communication over time, confirming subsurface fracture propagation. These findings can poten- tially save millions of dollars for the oil industry through targeted completion designs, which will ultimately increase efficiency and asset value. Subsurface DNA is obtained from reservoi r f luids, wel l cut t ings, and cores. Samples are collected in the field through noninvasive methods, which do not require pumping any chemicals into the reservoir. Biota works with mudlog- gers and pumpers to safely acquire samples during normal drilling and pro- duction processes, then samples are returned to the lab where DNA is extracted using techniques designed 42 APRIL 2018 WorldWide Drilling Resource ® Planning and Drilling the Blast Pattern Adapted from Information by U.S. Department of the Interior’s Office of Surface Mining Good blasting practices start with the accurate layout and drilling of blastholes in their planned or sometimes unplanned locations. For a single blast, these locations rarely form a uniform, rectangular grid. Each blast layout will present new or challenging design elements depending on the performance of previous blasts nearby, geology, or production requirements. Large mining operations may use high-capacity drill rigs with GPS technology and onboard computers to precisely position the rigs in each blasthole location. A planning engineer is often responsible for laying out and entering the locations for drill holes into a computer. This information is then transfered to the rig’s computer, and the drill is guided by GPS to reach drill hole position. Since the late 1980s, lasers and computer imaging software have been used as plan- ning tools to advance safe drilling and blasting in an economical manner. 3-D laser profiling allows drilling and blasting professionals to visualize the rock face and determine the face profile on the computer, which assists them in planning blasthole patterns, optimum bur- den dimensions, and explosives loading. Within the bounds of the planned blast, equipment is used to transmit a laser beam and receive accurate position information in x-y-z coordinates from beam reflections for millions of points on the highwall be- tween the crest and toe of the bench. This data is collected in some form of logger, and downloaded to the computer. In 2-D profiling, the proposed drill angle and hole offset from the crest are entered into the software, and profiles of the rock face and planned borehole are created graphically. 3-D profiling includes a survey of the actual drilled blastholes over the hole length from the hole collar, allowing for calculation of the effect of the hole deviations and computation of the explosive loading required from actual burden dimensions. Profiles of a bench may be interpreted by the software and printed out on a thermal printer in the field. The burdens over the length of each blasthole can be computed, allowing adjustments to be made in explosive quantities, location, or delay timing. Subsurface DNA cont’d on page 52.