Fiber-optic distributed strain sensing(FO-DSS)has been successful in monitoring strain changes along horizontal wellbores in hydraulically fractured reservoirs.However,the mechanism driving the various FO-DSS response...Fiber-optic distributed strain sensing(FO-DSS)has been successful in monitoring strain changes along horizontal wellbores in hydraulically fractured reservoirs.However,the mechanism driving the various FO-DSS responses associated with near-wellbore hydraulic fracture properties is still unclear.To address this knowledge gap,we use coupled wellbore-reservoir-geomechanics simulations to study measured strain-change behavior and infer hydraulic fracture characteristics.The crossflow among fractures is captured through explicit modeling of the transient wellbore flow.In addition,local grid refinement is applied to accurately capture strain changes along the fiber.A Base Case model was designed with four fractures of varying properties,simulating strain change signals when the production well is shut-in for 10 d after 240 d of production and reopened for 2 d.Strain-pressure plots for different fracture clusters were used to gain insights into inferring fracture properties using DSS data.When comparing the model with and without the wellbore,distinct strain change signals were observed,emphasizing the importance of incorporating the wellbore in FO-DSS modeling.The effects of fracture spacing and matrix permeability on strain change signals were thoroughly investigated.The results of our numerical study can improve the understanding of the relation between DSS signals and fracture hydraulic properties,thus maximizing the value of the dataset for fracture diagnostics and characterization.展开更多
In this study,flowback-assisted minifrac tests were conducted in low-permeability shale and salt formations to measure the in situ stress.An injection/flowback testing protocol was implemented in each test to achieve ...In this study,flowback-assisted minifrac tests were conducted in low-permeability shale and salt formations to measure the in situ stress.An injection/flowback testing protocol was implemented in each test to achieve accuracy and efficiency.Accurate and efficient injection/flowback testing is very important,given the impermeable nature of these formations and the need to complete each test as quickly as possible.Each flowback cycle yields a distinct and repeatable fracture closure signature,simplifying the interpretation of the fracture closure pressure.The objective of this paper is to share our field experience and to present a numerical analysis of the flowback test pressure responses,fracture closure behaviors,and fracture closure diagnostic methods.Examples from open-hole and casedhole minifrac tests are used to demonstrate site operation procedures.Then,two numerical models are presented for simulating the fracture closure behavior during a flowback test.Field evidence is provided to demonstrate that the fracture closure pressures from the flowback tests are identical to those from tests without flowback.The fracture closure diagnostic methods for flowback tests are discussed,and it is found that the G-function diagnostic method yields a distinct fracture closure signal during the flowback tests.This study is intended to provide additional insights regarding flowback tests by sharing our successes,experience,and knowledge,thereby benefiting the industry.展开更多
A 34-year-old man with a subtrochanteric osteoid osteoma localized to the lateral cortex of the left femur is reported. The patient presented with mild spontaneous pain of the lateral thigh and knee. He refused a radi...A 34-year-old man with a subtrochanteric osteoid osteoma localized to the lateral cortex of the left femur is reported. The patient presented with mild spontaneous pain of the lateral thigh and knee. He refused a radiographic examination and was treated as a greater trochanteric pa in syndrome for 9 months. He was then admitted with a transcervical fracture of the neck of the left femur after a fall from standing height. The fracture was fixed with 3 cannulated screws and healed uneventfully. His symptoms worsened after the first postoperative year. Eighteen months postoperatively the pain was dull, worsening at night, and relieved only with anti-inflammatory drugs, and he had a limp. New radiographs and tomograms were indicative of a lateral subtrochanteric osteoid osteoma with a subperiosteal localization. The lesion was treated successfully with surgical excision of a piece of reactive bone including the nidus.展开更多
基金funding support from the National Natural Science Foundation of China(Grant No.52204030)Youth Innovation and Technology Support Program for Higher Education Institutions of Shandong Province,China(Grant No.2022KJ070)the National Natural Science Foundation of China Enterprise Innovation and Development Joint Fund Project(Grant No.U19B6003).
文摘Fiber-optic distributed strain sensing(FO-DSS)has been successful in monitoring strain changes along horizontal wellbores in hydraulically fractured reservoirs.However,the mechanism driving the various FO-DSS responses associated with near-wellbore hydraulic fracture properties is still unclear.To address this knowledge gap,we use coupled wellbore-reservoir-geomechanics simulations to study measured strain-change behavior and infer hydraulic fracture characteristics.The crossflow among fractures is captured through explicit modeling of the transient wellbore flow.In addition,local grid refinement is applied to accurately capture strain changes along the fiber.A Base Case model was designed with four fractures of varying properties,simulating strain change signals when the production well is shut-in for 10 d after 240 d of production and reopened for 2 d.Strain-pressure plots for different fracture clusters were used to gain insights into inferring fracture properties using DSS data.When comparing the model with and without the wellbore,distinct strain change signals were observed,emphasizing the importance of incorporating the wellbore in FO-DSS modeling.The effects of fracture spacing and matrix permeability on strain change signals were thoroughly investigated.The results of our numerical study can improve the understanding of the relation between DSS signals and fracture hydraulic properties,thus maximizing the value of the dataset for fracture diagnostics and characterization.
文摘In this study,flowback-assisted minifrac tests were conducted in low-permeability shale and salt formations to measure the in situ stress.An injection/flowback testing protocol was implemented in each test to achieve accuracy and efficiency.Accurate and efficient injection/flowback testing is very important,given the impermeable nature of these formations and the need to complete each test as quickly as possible.Each flowback cycle yields a distinct and repeatable fracture closure signature,simplifying the interpretation of the fracture closure pressure.The objective of this paper is to share our field experience and to present a numerical analysis of the flowback test pressure responses,fracture closure behaviors,and fracture closure diagnostic methods.Examples from open-hole and casedhole minifrac tests are used to demonstrate site operation procedures.Then,two numerical models are presented for simulating the fracture closure behavior during a flowback test.Field evidence is provided to demonstrate that the fracture closure pressures from the flowback tests are identical to those from tests without flowback.The fracture closure diagnostic methods for flowback tests are discussed,and it is found that the G-function diagnostic method yields a distinct fracture closure signal during the flowback tests.This study is intended to provide additional insights regarding flowback tests by sharing our successes,experience,and knowledge,thereby benefiting the industry.
文摘A 34-year-old man with a subtrochanteric osteoid osteoma localized to the lateral cortex of the left femur is reported. The patient presented with mild spontaneous pain of the lateral thigh and knee. He refused a radiographic examination and was treated as a greater trochanteric pa in syndrome for 9 months. He was then admitted with a transcervical fracture of the neck of the left femur after a fall from standing height. The fracture was fixed with 3 cannulated screws and healed uneventfully. His symptoms worsened after the first postoperative year. Eighteen months postoperatively the pain was dull, worsening at night, and relieved only with anti-inflammatory drugs, and he had a limp. New radiographs and tomograms were indicative of a lateral subtrochanteric osteoid osteoma with a subperiosteal localization. The lesion was treated successfully with surgical excision of a piece of reactive bone including the nidus.
