Shale Reservoir Characterization--Pulling the Best Out of Your 3D Seismic Data
TOTAL, Secondee to Chesapeake Energy
Although the industry started extensively developing shale plays almost a decade ago, our discipline is still trying to find its proper role in this rapidly changing environment. We have all once heard managers saying: - Why shoot seismic in a shale play? - There are no structures, so there is no need for seismic! - Seismic, what for?! I can drill and complete two wells instead!
This talk aims at demystifying many questions around the usefulness of seismic in shale reservoirs and at showing how to adapt our conventional methods to unconventional plays. Using the Utica shale as an example, I will show how by carefully revisiting our conventional techniques, we are able to identified “sweet spots” based on 1) petrophysical and geomechanical properties obtained from seismic inversion and 2) natural fracture density and orientation derived from seismic azimuthal anisotropy. The reservoir team then matches production and EUR through simulation to define correlations that are used to evaluate and rank these “sweet spots”. With this methodology, we are creating a paradigm shift by moving from carpet bombing i.e. indiscriminate drilling of all acreage in an area, to surgical strike i.e. drilling first the best acreage with the optimal well spacing and completion.
During the talk, I will discuss the following topics: 1) Mapping pore pressure in shales based on seismic and sonic velocities 2) Characterizing natural fractures density and orientation based on seismic azimuthal anisotropy 3) Deriving petrophysical (clay volume, volume of organic matter, water saturation, effective porosity) and geomechanical (brittleness index) properties based on seismic prestack inversion 4) Incorporating pore pressure, fractures density and orientation and petrophysical properties to calculate production forecast and reserves 5) Estimating Net Present Value and/or Rate of Return per lease and rank leases by value - a result used to determine which leases to hold or to let expire and 6) Optimizing well spacing by accounting for natural fractures. I will spend most of the time on points 1 to 3 and rapidly go through points 4 to 6 that belong to the realm of reservoir engineering.
Alexandre Araman is French and grew up in Lebanon. He graduated from the Paris Institute of Technology with an Engineering degree and then obtained two MSc degrees in Digital Communication and Signal Processing from Imperial College London in 2007 and in Geophysics from Colorado School of Mines in 2009 working jointly with Ilya Tsvankin and Tom Davis. He then joined TOTAL and has worked there since. He started his career in Pau, France, as a reservoir geophysicist focusing on deterministic and stochastic inversions. He also worked on feasibility studies for 4D seismic projects and on AVO for prospect de-risking. Given his background, it was not surprising that Alexandre was assigned to the seismic processing group in 2011. He coordinated and supervised seismic data processing by major service companies as well as small independents. Regular visits to different processing centers in London and Paris as well as Russia, Poland and Egypt were parts of his duties. He also worked on seismic vessels and participated in two exploration campaigns in Ivory Coast and Myanmar handling the onboard fast-track processing. In 2013, he followed a TOTAL intensive training covering all theoretical, operational and safety aspects of well site geology. He was then assigned to drilling rigs in Abu Dhabi and Uganda before being sent to a semi-submersible offshore Congo where he spent 18 months. He geosteered horizontal drains in 2 to 3 feet thick reservoir targets in both carbonate and silico-clastic environments. His work also involved updating pore pressure prognosis while drilling, supervising mudlogging, LWD, VSP and wireline services companies and performing onsite data QC. Early 2015, he was sent to Oklahoma City to work with Chesapeake on the Utica shale. His work mainly focuses on anisotropy, fracture detection and characterization, elastic inversions for petrophysical and geomechanical properties and pore pressure prediction from wireline and seismic data.
Throughout his career, Alexandre acquired a transverse 2G (Geophysics/Geology) profile in exploration and development with a polyvalent experience in conventional and unconventional fields from basin-scale analysis to reservoir characterization. He has a broad experience in operations from seismic acquisition and processing to well planning and drilling. He has both offshore and onshore field experience on seismic vessels and drilling rigs. Alexandre is quadrilingual – he speaks French, Russian, English and Arabic – and is comfortable in multicultural environments. He actually holds a BSc in Russian Studies and is passionate about literature. He is also fond of board sports, especially kiteboarding and snowboarding that he practices at a high level. He also practices climbing and sailing. That’s probably why he spends all his free time kiteboarding or sailing on Lake Hefner and most of his vacation climbing or snowboarding in Colorado.