No one can pretend that nuclear engineering is simple.Far from it.But the next best thing is experience-lots of it-and no company can offermore experience or a more responsive service than BNFL Engineering Ltd.As the ...No one can pretend that nuclear engineering is simple.Far from it.But the next best thing is experience-lots of it-and no company can offermore experience or a more responsive service than BNFL Engineering Ltd.As the engineering arm of BNFL we are able to call on over 40 yearsof experience that provides our customers with valuable operational feedback,展开更多
In the Huangjinba Block of the Zhaotong National Shale Gas Demonstration Zone in the periphery of the Sichuan Basin,two horizontal shale gas wells suffer severe casing deformation.In this paper,the geological and engi...In the Huangjinba Block of the Zhaotong National Shale Gas Demonstration Zone in the periphery of the Sichuan Basin,two horizontal shale gas wells suffer severe casing deformation.In this paper,the geological and engineering characteristics of the strata around the deformed casing interval were analyzed based on the 24-arm caliper measurement of casing deformation,open-hole caliper,electrical resistivity,drilling time and gas logging,cementing CBLyVDL and CBL imaging.Then,24-arm caliper measurement data were analyzed and 3D imaged by 3D imaging analysis software,to figure out the morphologic characteristics of deformed casing.It is shown that severe casing deformation tends to occur where structural fractures are developed.Besides,casing deformation is mainly in the form of“S”-shape bending vertically.The severely deformed casing is also characterized by obviously transverse shear deformation caused by the high-angle sliding compression of rocks.Therefore,some suggestions were proposed correspondingly.First,the countermeasures in this block shall focus on shear casing deformation caused by the sliding of rocks along the fracture face.Wellbore trajectory shall be designed based on the structural contours map of pay zones to bypass the“ridge”and“valley bottom”area in the local high and steep structural zones.Second,the distribution information of fractured zones shall be predicted based on the ant-tracking attribute volume distribution map of pay zones,so that the wellbore trajectory can run along the strike of fractured zone.And third,it is recommended to use plug-drilling free big bore bridge plug or full-bore infinite stage completion technique,so that the conventional bridge plug milling operation after fracturing can be omitted and each fractured layer can be put into production after fracturing.展开更多
The world is trying to recover from once in the COVID-19 pandemic, which has a higher mortality rate than the common flu. However, the threat of different variants is still affecting us in a different capacity. Severa...The world is trying to recover from once in the COVID-19 pandemic, which has a higher mortality rate than the common flu. However, the threat of different variants is still affecting us in a different capacity. Several preventive measures have been adopted across the nation and the globe to avoid the spr<span style="font-family:Verdana;">ead of this virus, such as lockdown, restricted travel, social distancing guidelin</span><span style="font-family:Verdana;">es, obligatory face mask use, etc. These activities directly influenced the manag</span><span style="font-family:Verdana;">ement of social life, economy, and livelihoods. The effect of COVID-</span><span style="font-family:Verdana;">19 on the public transit industry and strategies the transit agencies adapted to continue providing the service during the pandemic has been synthesized in this pap</span><span style="font-family:Verdana;">er. As a result of the pandemic, public transit ridership decreased by abou</span><span style="font-family:Verdana;">t 70 percent for most agencies compared to pre-pandemic levels. This article also highlights the prevention of COVID-19 spread in the public transit industry using engineering solutions and advanced material science and nanotechnology solutions.</span>展开更多
In this paper, processes for producing a food-grade glucose solution through enzymatic hydrolysis of celluloserich solids obtained from rice straws are presented. The rice straws were pretreated by acid-catalyzed stea...In this paper, processes for producing a food-grade glucose solution through enzymatic hydrolysis of celluloserich solids obtained from rice straws are presented. The rice straws were pretreated by acid-catalyzed steam explosion, and the reaction efficiency, toxicity control, and process economic feasibility were studied. Mass transfer resistance to the hydrolysis reaction was reduced by grinding with glass beads. A higher glucose concentration could be obtained by feeding more cellulose in the hydrolysis reaction; however, this also resulted in the production of undesired byproducts. Thus, a soaking process for the cellulose solids in water was developed to effectively reduce the generation of byproducts in the hydrolysis reaction. The resulting food-grade glucose solution can provide 414 kilocalories per liter, and could be used during a food-shortage crisis in the future.The current production cost is estimated to be 0.82 USD·L^(-1).展开更多
文摘No one can pretend that nuclear engineering is simple.Far from it.But the next best thing is experience-lots of it-and no company can offermore experience or a more responsive service than BNFL Engineering Ltd.As the engineering arm of BNFL we are able to call on over 40 yearsof experience that provides our customers with valuable operational feedback,
文摘In the Huangjinba Block of the Zhaotong National Shale Gas Demonstration Zone in the periphery of the Sichuan Basin,two horizontal shale gas wells suffer severe casing deformation.In this paper,the geological and engineering characteristics of the strata around the deformed casing interval were analyzed based on the 24-arm caliper measurement of casing deformation,open-hole caliper,electrical resistivity,drilling time and gas logging,cementing CBLyVDL and CBL imaging.Then,24-arm caliper measurement data were analyzed and 3D imaged by 3D imaging analysis software,to figure out the morphologic characteristics of deformed casing.It is shown that severe casing deformation tends to occur where structural fractures are developed.Besides,casing deformation is mainly in the form of“S”-shape bending vertically.The severely deformed casing is also characterized by obviously transverse shear deformation caused by the high-angle sliding compression of rocks.Therefore,some suggestions were proposed correspondingly.First,the countermeasures in this block shall focus on shear casing deformation caused by the sliding of rocks along the fracture face.Wellbore trajectory shall be designed based on the structural contours map of pay zones to bypass the“ridge”and“valley bottom”area in the local high and steep structural zones.Second,the distribution information of fractured zones shall be predicted based on the ant-tracking attribute volume distribution map of pay zones,so that the wellbore trajectory can run along the strike of fractured zone.And third,it is recommended to use plug-drilling free big bore bridge plug or full-bore infinite stage completion technique,so that the conventional bridge plug milling operation after fracturing can be omitted and each fractured layer can be put into production after fracturing.
文摘The world is trying to recover from once in the COVID-19 pandemic, which has a higher mortality rate than the common flu. However, the threat of different variants is still affecting us in a different capacity. Several preventive measures have been adopted across the nation and the globe to avoid the spr<span style="font-family:Verdana;">ead of this virus, such as lockdown, restricted travel, social distancing guidelin</span><span style="font-family:Verdana;">es, obligatory face mask use, etc. These activities directly influenced the manag</span><span style="font-family:Verdana;">ement of social life, economy, and livelihoods. The effect of COVID-</span><span style="font-family:Verdana;">19 on the public transit industry and strategies the transit agencies adapted to continue providing the service during the pandemic has been synthesized in this pap</span><span style="font-family:Verdana;">er. As a result of the pandemic, public transit ridership decreased by abou</span><span style="font-family:Verdana;">t 70 percent for most agencies compared to pre-pandemic levels. This article also highlights the prevention of COVID-19 spread in the public transit industry using engineering solutions and advanced material science and nanotechnology solutions.</span>
基金the Ministry of Science and Technology of Taiwan for financially supporting this research under Contract No.NSC-1022623-E-002-012-ET
文摘In this paper, processes for producing a food-grade glucose solution through enzymatic hydrolysis of celluloserich solids obtained from rice straws are presented. The rice straws were pretreated by acid-catalyzed steam explosion, and the reaction efficiency, toxicity control, and process economic feasibility were studied. Mass transfer resistance to the hydrolysis reaction was reduced by grinding with glass beads. A higher glucose concentration could be obtained by feeding more cellulose in the hydrolysis reaction; however, this also resulted in the production of undesired byproducts. Thus, a soaking process for the cellulose solids in water was developed to effectively reduce the generation of byproducts in the hydrolysis reaction. The resulting food-grade glucose solution can provide 414 kilocalories per liter, and could be used during a food-shortage crisis in the future.The current production cost is estimated to be 0.82 USD·L^(-1).
