Hydraulic Fracture Diagnostics Used To Optimize Development in the Jonah Field

摘要

This paper reports on a study conducted to assist with fieldrndevelopment in the Jonah Field in Wyoming. Microseismicrnand surface tiltmeter fracture mapping was performed on tenrnwells in two areas of the field and over 100 fracture treatmentsrnwere mapped. The fracture mapping study was performed asrnpart of a pilot project to evaluate ten-acre well spacing.rnThe Jonah Field is located in the Green River Basin inrnSublette County, WY. Production is primarily from overpressuredrnand tight sandstones of the Lance Formation. ThernLance in Jonah consists of many stacked low permeabilityrnsandstones. Due to the low permeability, stimulation isrnrequired for economical production rates. Gross pay intervalsrnvary from 2,800 ft to 3,600 ft and wells are stimulated inrnmultiple fracture stages. Each fracture stage may target threernto six sands with eight to twelve total stages for each well.rnThe study shows mapping results for fracture treatments inrnboth mapping areas. Fracture length was longer than expectedrnand varied somewhat by stage. Some stages were containedrnbut for many stages there was significant height growth andrntreatment overlap. Fracture complexity was observed whichrncould be due to natural fracturing, faulting, depositionalrnheterogeneity and depletion.rnThese fracture mapping results are being combined withrngeologic, geophysical and engineering data from the field tornassist with field development. This paper details the results ofrnthe mapping and discusses issues with well placement,rnstimulation design and treatment staging identified by thernstudy.