Advanced Hydraulic Fracturing Treatments in the Wushenqi Low-Permeability GasField: A Workflow to Minimize the Learning Curve

摘要

The Wushenqi gas field is a low permeability gas play underrndevelopment by the Changqing Oilfield Company ofrnPetroChina (PCOC). The first well in this field was drilled andrnhydraulically fractured in 1994. Out of the ten wells initiallyrndrilled, nine were hydraulically fractured using a design basedrnon historical knowledge and area best practices. The averagerngas production of the 10 wells was 586000 scf/day (16,600rnm3/day), which was less than the production required forrneconomical development of the field.rnThis paper details how Changqing Oil Company andrnSchlumberger used an optimization workflow and integratedrnstudy to improve the completion procedure and increase wellrnproductivity. A new field development plan was created basedrnon the following:rn· Advanced seismic interpretation.rn· Geological and petrophysical analysis.rn· Analysis of postfracturing production data.rn· Production forecasts from a new reservoir model andrna model of hydraulic fracturing optimization.rn· Completion optimization.rn· Economic evaluation.rnSome of the significant results from the study include:rn1. An improved understanding of the location of thernsand bodies resulting in better control on placementrnof new wells.rn2. A correlation which adjusted the log-derivedrnpermeabilities in order to more closely matchrnpermeabilities obtained from transient testing andrnproduction analysis.rn3. An improved well design reflecting data acquisition,rnfracturing process, and production requirements.rn4. A modified fracturing treatment d esign tailored forrnthe expected Kh and deliverabilty requirements of thernvarious zones.rn5. An on-site test program using pre-fracture treatmentrninjection testing to verify the permeability.