Techniques

Overview

Each of these core sample analysis techniques, performed in GeoMark labs, provide useful data for calibrating models, constraining properties, and impacting business decisions based on subsurface data.

TOC and Programmed Pyrolysis

The following data are provided: organic enrichment, kerogen type, source rock generative capacity, source rock quality, calibration of geological-geochemical and petrophysical models, existing volatile fraction, geochemically based original oil-in-place, kinetic modeling for basin modeling constraint (generative capacity and expulsion), seal effectiveness, thermal maximum/thermal maturity, and lithological model calibration.

Thermally or Chemically Extracted Fluids and Analysis

The following data are provided: Geochemical fingerprinting, time-lapse geochemistry calibration, maturity, charge and migration understanding, fluid loss quantification, comparison of mobile versus immobile compositions/fluid types/flavors to produced fluid

TruSat Rock Properties

The following data are provided: grain volumes, total porosity, dual retort oil, and water saturations, including free versus bound fluid volumes (a unique thermal and solvent-based extraction technique). (Refer to the link below to access the diagram.)

Click here for the TruSat™ Work Flow Diagram

• NMR T1/T2 acquisition and 2D map capability

  • T2 distributions can be utilized for fluid-filled pore body quantification and understanding.
  • T1/T2 results can be utilized for potential fluid typing and understanding of lost fluid fraction.

• Open and closed retort capability

  • Assess the free versus bound water results (i.e. water partitioning). This can be compared to NMR results.
  • Mobile versus immobile hydrocarbon fraction (i.e. hydrocarbon partitioning).

• Geochemical integration of TOC and programmed pyrolysis data (can be complimented by fluid property analysis)

  • Differentiates the thermally versus chemically extracted results for an understanding of mobile versus immobile organic matrix components.
  • Offers TOC calibration for all subdisciplines.
  • Provides thermal maturity (Tmax) understanding, as well as volatile fluid fraction (S1 mg/g) versus remaining source rock potential constraint (S2 mg/g).

Why Take Core Samples?

Subsurface core samples provide rock property constraints through measured laboratory techniques. They are the results that subsurface models are calibrated to in order to change from a qualitative to a quantitative evaluation—to help predict and better understand oil and gas reserves.

Best Practices

Overview

Proper sample handling and careful transportation of cores from your wellsite to the laboratory is a key element of any core analysis program. Improper practices can negatively impact the final data generated within the laboratory. To minimize fluid loss and ensure consistent and reliable core data, particularly in tight rock formations, GeoMark recommends the below best practices procedure (however, applicability of legacy core volume is noted and viable).

Procedure

Follow these steps to ensure sample handling and transportation do not compromise your core plugs or RSWCs:

1. Each sample should be wiped off with a dry cloth and weighed (if possible/practical).
   • Gently wipe each sample and not in excess (do not rub dry, just enough to remove the outer layer of mud cake, if present).
2. Wrap each sample individually with 2-3 layers of foil, followed by 7-8 layers of saran wrap.
3. Place wrapped RSWCs into plastic jars (avoid glass), while inserting additional plastic wrap to take up space in jar to minimize core movement.
4. Label each plastic jar, indicating sample number and/or depth.
5. Tightly seal the plastic jar and wrap lid with 2-3 layers of electrical tape.
6. Plastic jars should be placed into a chilled transport container, such as an ice cooler or ice chest, with dry ice or ice packs sufficient to keep cores cooled, without freezing, for the duration of the trip to the lab.
   • Ask shipping personnel to transport the package in the cab, and not in the back of a truck where temperatures can quickly elevate.
7. Place temperature monitor device inside cooler (if possible/practical).
8. Create an electronic core inventory and shipping list details (chain-of-custody) to be forwarded to the receiving location and client.
9. As soon as possible, have your samples driven or “Hot-Shot” to GeoMark’s Telge location:

GeoMark Research

ATTN: Alex Zumberge

9748 Whithorn Drive

Houston, TX 77095