The Haynesville shale is characterized by high TOC, good porosity, high gas saturation, low clay content and nanoDarcy permeabilities, all which makes for an exceptional shale gas reservoir. However, recent well IP's have been variable, and given the planned extensive development, it is necessary to de-risk some of the geologic variables to up-grade acreage and optimize well development plans. This was done through a two-part study covering the greater Sabine area of northwestern Louisiana, USA. The first part focused on defining the depositional environment, reservoir characteristics, and facies variation through inorganic element analysis, XRF, XRD, petrography, and biostratigraphic classification of macro- and nanofossils. The second focused on interpretation of present-day stresses and characterization of the natural fracture from core, image logs, and micro-seismic data. Both parts were then integrated to assist in sweet spot definition and well planning and optimization.
Results suggest that the Haynesville’s reservoir properties (clay/calcite content, TOC, perm) are mappable showing trends that can roughly be correlate with IP rates. However, on a well-to-well basis, it is unclear what the contribution of a single property is (e.g., TOC or porosity) to productivity, and hence the predictability of future well rates or location. Similarly, fracture distribution shows mappable trends. These fractures are generally calcite cemented, and hence cannot directly contribute to well productivity unless reactivated during the stimulation. Vertically, fractures occur more extensively in the lower and upper Bossier than in the Haynesville and Mid-Bossier forming a mechanically layered system.
The Haynesville Shale’s proposed or adopted drilling and production units cover 1.5 million acres. That is not including the Texas side. Considering a development spacing of 160 acres per well, that is nearly 90-95k wells, of which only 2000 are drilled.
No comments:
Post a Comment