FAST PRESSURE-DECAY CORE PERMEABILITY MEASUREMENT FOR TIGHT ROCKS
Seminar Date: Apr 26 2019
Registration Opens: Apr 16 2019 - Apr 25 2019
Time: 11:30 AM - 01:00 PM (US CDT)
Admission/Registration Link: None
Meeting/Webinar Link: None
Contact: Jeff Crawford ( Houston, TX, USA, SPWLA Houston Chapter)
For Student: $10
For Member: $10
For Non-member: $15
Matrix permeability is one of the most important factors used to evaluate the long-term production of hydrocarbon reservoirs. However, for shale reservoirs that have ultra-low matrix permeability in the range of tens to hundreds of nano-darcies (nd), the laboratory measurement of the matrix permeability of intact (non-particle-sized) samples has remained a challenge. The widely-used measurement methods such as pulse-decay and steady-state have two primary limitations: (1) measurements take hours or even days and (2) commonly-present sample fractures affect the measured permeability value. In this study, a new pressure-decay permeability method is proposed for ultra-tight rocks to overcome these limitations. The principle of the pressure-decay experiment is that system gas pressure is higher than pore pressure of the core sample so that gas penetrates the core sample and permeability is derived from the decrease of system gas pressure. In order to validate the proposed pressure-decay technique, experiments were conducted on the following intact rock samples: (1) a set of different types of rocks including a Marcellus shale plug, (2) a set of Eagle Ford shale plugs, and (3) a Marcellus shale plug with open, connected fractures. A series of comparative studies of the permeability results from pressure-decay, pulse-decay, and steady-state experiments on these core samples confirmed that the proposed pressure-decay experiment can provide accurate matrix permeability of ultra-tight rocks. Tests can be completed within one hour and the measurement range is from 1.0e-01 md to 1.0e-06 md. Further, the proposed method has the following advantages: (1) measured matrix permeability by the new pressure-decay method isn’t affected by the open, connected fractures, whereas these fractures can make the pulse-decay and steady-state permeability results increase by three orders of magnitude, (2) the new pressure-decay experiment is around 10 times faster than the pulse-decay experiment and 20 times faster than the steady-state experiment, and (3) the proposed pressure-decay experiment can provide the gas-filled pore and fracture volumes during the permeability measurement, whereas pulse-decay and steady-state experiments cannot.
Zheng “Jon” Gan is Technical Advisor for the Petroleum Services Division of Core Laboratories in Houston, TX. He received a B.S. degree in mathematics from University of Science and Technology of China in 2007, and a PhD degree in mathematics from Rice University in 2012. Dr. Gan joined Core Lab in 2013, and as Technical Advisor he works on statistical analysis, mathematical modeling, software development, and experimental design and set up for various core analysis projects such as Permeability and Porosity Measurements, Digital Rocks, NMR, and EOR. He focuses on improving Core Lab’s existing core analysis services and developing new core analysis technologies, especially for tight shales.
Parking Info: Visitors are requested to reverse park, note their license plate number, and sign in at the main reception.
Please register by Apr 23rd, 2019 @ 12 pm to reserve lunch and pre-registration
Contact: Fransiska Goenawan
Corresponding: email@example.com // 281-460-8692