Results of the 2019 U.S.Geological Survey Assessment of Water and Proppant Associated with Petroleum Production from the Eagle Ford Group,Texas

摘要

The U.S.Geological Survey(USGS)recently completed an assessment of water and proppant demands associated with petroleum production from the Upper Cretaceous Eagle Ford Group in South Texas.The water and proppant assessment builds on the 2018 petroleum assessment conducted by the Energy Resources Program of the USGS,and the assessed water and proppant quantities correspond with the undiscovered technically recoverable resource estimated in the 2018 petroleum assessment.We will present the results and a summary of the methods used in the water assessment which include estimates of water needed for drilling and cement,water needed to hydraulically fracture wells,proppant needed to perform hydraulic fracturing,and produced water from the Eagle Ford Group.The impacts of water demand and the requirements of wastewater disposal are key issues in planning and developing unconventional(continuous)petroleum resources in rural areas such as arid South Texas.While the number of annually drilled oil and gas wells has declined in recent years,the amounts of water and proppant needed to hydraulically fracture each new well have increased over time.This is partly related to an increase in lateral lengths but also due to an overall increase in water volume per lateral foot.Proppant demands have also increased,while proppant-to-water ratios have remained relatively constant over the last six years.Each new well adds to the total water from formation that is produced and requires either recycling or wastewater disposal.The intent of this assessment is to provide geology-based estimates of the water and proppant resources potentially needed to extract the estimated undiscovered technically recoverable petroleum from the Eagle Ford Group.By linking estimates of future water and proppant demands and produced water volumes with undiscovered petroleum resources,we provide information to support informed planning.