The past six years （2008-2014） was a prosperous time for exploration and production in the dGOM （deepwater Gulf of Mexico）. Recent exploration and production activities can be divided into three major categories：...The past six years （2008-2014） was a prosperous time for exploration and production in the dGOM （deepwater Gulf of Mexico）. Recent exploration and production activities can be divided into three major categories： drilling new wildcat wells, appraising and developing newly discovered fields and enhanced oil recovery of mature fields. Seismic imaging, complex geology, high pressure drilling, greater depth, and higher temperature are key challenges for the exploration and production of dGOM reservoirs. Complex geology includes salt-related structures and traps, reservoir compartmentalization, and the sequence stratigraphy of turbidite reservoirs. Turbidite sequence stratigraphy helps the asset team to fred the best target intervals. Sheet and channelized sandstones with good downdip aquifer support are preferred reservoir conditions. All the drilling, development and production challenges are related to high pressure, greater depth, higher temperature and lack of existing field analogs. Various IOR （improved oil recovery） methods are studied and applied in the development stage of the Wilcox fields, which have an average primary recovery factor of 10%-15%. With ideal tabular reservoir geometry and IOR methods, recovery factor of the Wilcox reservoirs can reach up to 42% of OOIP （origional oil in place） through the field life cycle.展开更多
It is well-known that barriers have a significant impact on the production performance of horizontal wells developed in a bottom water drive reservoir. In most cases, reservoir barriers are semi-permeable. Based on pr...It is well-known that barriers have a significant impact on the production performance of horizontal wells developed in a bottom water drive reservoir. In most cases, reservoir barriers are semi-permeable. Based on previous research on impermeable reservoir barrier, a mathematical flow model was derived for a horizontal well of a bottom water drive reservoir with a semi-permeable barrier. Besides, analytical equations were also presented to calculate critical parameters, such as production rate,pressure and potential difference. The effects of barrier, well and reservoir parameters on our model results were further investigated.The results show that the larger the barrier size is or the higher the barrier location is, the higher the critical production rate and potential difference of a horizontal well are. When the barrier permeability equals the formation permeability or the barrier width equals zero, the critical production rates converge to the values same to that of the case with no barrier. When the barrier permeability equals zero, the problem is regarded as a case of impermeable barrier. This model can be applied to predicting horizontal wells' critical production parameters in reservoirs with semi-permeable barriers.展开更多
Generally the irreducible water saturation of low permeability gas reservoir is quite high which leads to the permeability stress sensibility and threshold pressure gradient. Under the assumption that permeability var...Generally the irreducible water saturation of low permeability gas reservoir is quite high which leads to the permeability stress sensibility and threshold pressure gradient. Under the assumption that permeability varies with experimental law of the pseudo pressure drop, according to concepts of perturbable ellipses and equivalent developing regulations, the calculation method of stable production of hydraulically fractured gas well in low permeability reservoirs is investigated with threshold pressure. And productivity curve is drawn and analyzed. The result shows that, permeability modulus and threshold pressure have effect on production of fractured gas well. The higher the permeability modulus and the threshold pressure, the lower the production is. Therefore, the impact of stress sensitive and threshold pressure must he considered when analyzing the productivity of vertical fracture well in low permeability gas reservoir.展开更多
文摘The past six years （2008-2014） was a prosperous time for exploration and production in the dGOM （deepwater Gulf of Mexico）. Recent exploration and production activities can be divided into three major categories： drilling new wildcat wells, appraising and developing newly discovered fields and enhanced oil recovery of mature fields. Seismic imaging, complex geology, high pressure drilling, greater depth, and higher temperature are key challenges for the exploration and production of dGOM reservoirs. Complex geology includes salt-related structures and traps, reservoir compartmentalization, and the sequence stratigraphy of turbidite reservoirs. Turbidite sequence stratigraphy helps the asset team to fred the best target intervals. Sheet and channelized sandstones with good downdip aquifer support are preferred reservoir conditions. All the drilling, development and production challenges are related to high pressure, greater depth, higher temperature and lack of existing field analogs. Various IOR （improved oil recovery） methods are studied and applied in the development stage of the Wilcox fields, which have an average primary recovery factor of 10%-15%. With ideal tabular reservoir geometry and IOR methods, recovery factor of the Wilcox reservoirs can reach up to 42% of OOIP （origional oil in place） through the field life cycle.
基金Project(51404201)supported by the National Natural Science Foundation of ChinaProject(2011ZX05024-003)supported by the National Science and Technology Major Project of China+1 种基金Project(14ZB0045)supported by the Scientific Project of Sichuan Provincial Education Department,ChinaProject(2015JY0076)supported by Basic Application Research of Science and Technology Department of Sichuan Province,China
文摘It is well-known that barriers have a significant impact on the production performance of horizontal wells developed in a bottom water drive reservoir. In most cases, reservoir barriers are semi-permeable. Based on previous research on impermeable reservoir barrier, a mathematical flow model was derived for a horizontal well of a bottom water drive reservoir with a semi-permeable barrier. Besides, analytical equations were also presented to calculate critical parameters, such as production rate,pressure and potential difference. The effects of barrier, well and reservoir parameters on our model results were further investigated.The results show that the larger the barrier size is or the higher the barrier location is, the higher the critical production rate and potential difference of a horizontal well are. When the barrier permeability equals the formation permeability or the barrier width equals zero, the critical production rates converge to the values same to that of the case with no barrier. When the barrier permeability equals zero, the problem is regarded as a case of impermeable barrier. This model can be applied to predicting horizontal wells' critical production parameters in reservoirs with semi-permeable barriers.
文摘Generally the irreducible water saturation of low permeability gas reservoir is quite high which leads to the permeability stress sensibility and threshold pressure gradient. Under the assumption that permeability varies with experimental law of the pseudo pressure drop, according to concepts of perturbable ellipses and equivalent developing regulations, the calculation method of stable production of hydraulically fractured gas well in low permeability reservoirs is investigated with threshold pressure. And productivity curve is drawn and analyzed. The result shows that, permeability modulus and threshold pressure have effect on production of fractured gas well. The higher the permeability modulus and the threshold pressure, the lower the production is. Therefore, the impact of stress sensitive and threshold pressure must he considered when analyzing the productivity of vertical fracture well in low permeability gas reservoir.
