Augmented Reality: Simulation Enhanced Pressure Core Data

Erkal, Alpay (Noble Energy Inc.) | Christensen, Christopher (Noble Energy Inc.) | Powers, Garwin (Noble Energy Inc.) | DesAutels, Dave (Vaalco Energy Inc.)



Field development decisions are directly related to the original hydrocarbon in-place that leads to proper estimation of recoverable volumes and establish project economics. Oil and gas industry has had pressure core technology that is available to extract and preserve cores from reservoirs near in-situ conditions to determine hydrocarbon in-place values. Pressure core technology is an emerging one and prone to incomplete or partial data acquisition due to design limitations and inadequate implementations. Simulation modeling tool, typically used for reservoir modeling purposes, can augment the underperformances in data acquisition with a lab scale core simulation program.

Noble Energy has developed a modeling approach that allows hydrocarbon desorption rates from a pressure core sample to be simulated by emulating the lab conditions. Early time fluid losses for various reason such as fluid losses while encapsulating the core or during transport via wellbore and to the lab are common. Late time fluid desorption rates are difficult to obtain due to the time constraint that exists for performing experiments in the lab since it’s limited to hours to days timeframe. Both early and late time desorption rates can be augmented by simulation that yields better estimation of in-place volumes and expected recovery values over time while honoring the lab measured data in between.

Pressurized wireline rotary sidewall coring used by the vendors can have seal failures and the procedures implemented would not provide assurance of zero fluid losses since the mechanical equipment has expected operational limitations. The data obtained from such acquisitions may be deemed a failed experiment or even discarded if the losses cannot be quantified properly. Simulation enhancement revitalizes the data acquired and adds value to even partially successful pressure coring programs.

Noble Energy developed modeling approach to simulate fluid flow from the center of a core plug to the exterior surfaces of the plug emulating the lab environment complements the lab measurements even the pressure core had issues during and after acquisition. Simulation enhances pressure core data that may be incomplete or partially acquired based on possible early time losses and provide extended answers for late time desorption by eliminating impractical lab measurement timeframe. Reduced uncertainty in original hydrocarbon in-place volumes will allow better valuation of assets and robust field development plans.