The Power of Integrated Solutions Using Both Production Geochemistry and PVT
Petroleum geochemistry is one of the main petroleum system analysis (PSA) tools, and has a proven record of value-added applications along the whole lifecycle of petroleum asset development – from exploration and appraisal to development, production, abandonment and environmental remediation. Reservoir and production geochemistry refers to the applications of petroleum geochemistry mainly during the development and production of an asset. Appraisal is also a very important stage for production geochemistry because the information gathered at that stage defines the static conditions baseline of the reservoir to which the following dynamic production data are compared for many years to come. Reservoir and production geochemistry is one of the more recently developed (late 1980s - early 1990s) applications of petroleum geochemistry to oil and gas business. It utilizes subtle but measurable compositional differences in reservoir fluids (oil, gas, water) that are controlled by two main groups of factors: 1) variations in charge history (e.g., maturity and/or source rock of the fluids accumulating in the reservoir); 2) post- accumulation in-reservoir processes (e.g., biodegradation, leakage, water washing, charge mixing). The advancement of reservoir and production geochemistry clearly showed the need for integration of geochemistry with reservoir characterization, development geology and petroleum engineering, including PVTx (Pressure-Volume- Temperature-Composition). The present talk will discuss how geochemists and engineers apply PVTx, provide a brief historical overview of several concepts related to in-reservoir charge accumulation and alteration processes, and their impact on reservoir fluid properties for conventional reservoirs. Static and dynamic reservoir compartmentalization, compositionally graded columns and depletion, impact of in-reservoir charge mixing processes on reservoir fluid properties, production allocation, solving flow assurance (wax and asphaltene deposition) and production (well, pipeline leaks, oil spills) problems are some of the main integrated geochemistry-engineering applications to be reviewed. The unconventional oil and gas revolution of the last decade presented new challenges and opportunities for integration of geochemistry with engineering, including integration with drilling and completion engineering. Main applications to be discussed include identification of oil “sweet spots”, fractured/fault zones and reservoir compartments along lateral wells, evaluation of reservoir fluid properties from surface data, time-lapse geochemistry to monitor dynamic changes in stimulated and effective drained reservoir volumes and production allocation.
AAPG Datapages/Search and Discovery Article #90349 © 2019 AAPG Hedberg Conference, The Evolution of Petroleum Systems Analysis: Changing of the Guard from Late Mature Experts to Peak Generating Staff, Houston, Texas, March 4-6, 2019