Formation testing while drilling is an innovative technique that is replacing conventional pressure testing in which the fluid sampling is conducted in a relatively short time following the drilling. At this time, mud...Formation testing while drilling is an innovative technique that is replacing conventional pressure testing in which the fluid sampling is conducted in a relatively short time following the drilling. At this time, mud invasion has just started, mudcake has not formed entirely and the formation pressure is not stable. Therefore, it is important to study the influence of the downhole dynamic environment on pressure testing and fluid sampling. This paper applies an oil-water two phase finite element model to study the influence of mudcake quality and mud filtrate invasion on supercharge pressure, pretest and sampling in the reservoirs of different permeability. However, the study is only for the cases with water based mud in the wellbore. The results illustrate that the mudcake quality has a significant influence on the supercharge pressure and fluid sampling, while the level of mud filtrate invasion has a strong impact on pressure testing and sampling. In addition, in-situ formation pressure testing is more difficult in low permeability reservoirs as the mud filtrate invasion is deeper and therefore degrades the quality of fluid sampling. Finally, a field example from an oil field on the Alaskan North Slope is presented to validate the numerical studies of the effects of downhole dynamic conditions on formation testing while drilling.展开更多
This paper deals with a simulated test of biogenic mineralization made with a blue-green alga species,Spirulina platensix. The data in the experiment were recorded by a computerized surveying system. The influ-ence of...This paper deals with a simulated test of biogenic mineralization made with a blue-green alga species,Spirulina platensix. The data in the experiment were recorded by a computerized surveying system. The influ-ence of algae on the accumulation of phosphorus by changing their microenvironment to promote the forma-tion and deposition of phosphate was studied. The results show that the pH value of cultural liquor rose up to 10 and the redox potential (Eh) may dropby 100-200 mV during the algal logarithmic growth stage, and the cultrual liquor was changed into a mediumwith a weakly reducing condition. At the end of the logarithmic growth stage white deposits of Na_2Ca(CO_3)_2·5H_2O and Ca_2Mg (PO_4)_2·2H_2O were formed on the floor of cultural containers. The test presented a wduableevidence for the theory of biogenic mineralization.展开更多
A new method, which is based on formation fracturing test and Kaiser effect method, has been developed for confirming the oilfield in-situ stress in this paper. The new method has been used in a certain oilfield of Ch...A new method, which is based on formation fracturing test and Kaiser effect method, has been developed for confirming the oilfield in-situ stress in this paper. The new method has been used in a certain oilfield of China and the determined oilfield in-situ stresses is more accurate than that based on one single method.展开更多
Objective:To establish a simple and efficient culture method of primary rabbit brain microvascular endothelial cells,provide important carriers and tool cells for the research of related cerebrovascular diseases.Metho...Objective:To establish a simple and efficient culture method of primary rabbit brain microvascular endothelial cells,provide important carriers and tool cells for the research of related cerebrovascular diseases.Methods:The cerebral cortexes of rabbits were collected aseptic and inoculated after cutting,passing through cell sieve,bovine serum albumin density gradient centrifugation,typeⅡcollagenase digestion,finally inoculated and cultured.The cultured cells were identified by cell morphological observation and angiogenesis experiment.Results:Under the inverted microscope,the cells were short fusiform or polygonal,and grew in clusters and adhere to the wall.After the cells were densely fused,they would be in a typical monolayer flat,“pebbled"mosaic arrangement.Tube formation test had the ability to form tubes structure.Conclusion:This method can successfully separate and cultivate primary rabbit brain microvascular endothelial cells.展开更多
If tests are to provide an accurate measure of learners’ language abilities, examiners must minimize the influence of intervening factors such as response format. This article is to investigate the effects of two tes...If tests are to provide an accurate measure of learners’ language abilities, examiners must minimize the influence of intervening factors such as response format. This article is to investigate the effects of two test formats on Chinese EFL learners' performance in reading tests. The findings confirm that test-takers' performance on reading is significantly affected by test formats and language level. All groups perform better on MCQ (Multiple Choice Questions) than SAQ (Short Answer Questions). Both test format and language proficiency level have main effect but they do not have interactive effect. By paying more attention to these factors examiners will enhance the validity of their tests.展开更多
基金supported by the National Natural Science Foundation of China (No. 50674098)Major Project of Chinese Science and Technology (No. 2011ZX 05000-020-04)Major Project of SINOPEC Science and Technology (No. P13147)
文摘Formation testing while drilling is an innovative technique that is replacing conventional pressure testing in which the fluid sampling is conducted in a relatively short time following the drilling. At this time, mud invasion has just started, mudcake has not formed entirely and the formation pressure is not stable. Therefore, it is important to study the influence of the downhole dynamic environment on pressure testing and fluid sampling. This paper applies an oil-water two phase finite element model to study the influence of mudcake quality and mud filtrate invasion on supercharge pressure, pretest and sampling in the reservoirs of different permeability. However, the study is only for the cases with water based mud in the wellbore. The results illustrate that the mudcake quality has a significant influence on the supercharge pressure and fluid sampling, while the level of mud filtrate invasion has a strong impact on pressure testing and sampling. In addition, in-situ formation pressure testing is more difficult in low permeability reservoirs as the mud filtrate invasion is deeper and therefore degrades the quality of fluid sampling. Finally, a field example from an oil field on the Alaskan North Slope is presented to validate the numerical studies of the effects of downhole dynamic conditions on formation testing while drilling.
文摘This paper deals with a simulated test of biogenic mineralization made with a blue-green alga species,Spirulina platensix. The data in the experiment were recorded by a computerized surveying system. The influ-ence of algae on the accumulation of phosphorus by changing their microenvironment to promote the forma-tion and deposition of phosphate was studied. The results show that the pH value of cultural liquor rose up to 10 and the redox potential (Eh) may dropby 100-200 mV during the algal logarithmic growth stage, and the cultrual liquor was changed into a mediumwith a weakly reducing condition. At the end of the logarithmic growth stage white deposits of Na_2Ca(CO_3)_2·5H_2O and Ca_2Mg (PO_4)_2·2H_2O were formed on the floor of cultural containers. The test presented a wduableevidence for the theory of biogenic mineralization.
文摘A new method, which is based on formation fracturing test and Kaiser effect method, has been developed for confirming the oilfield in-situ stress in this paper. The new method has been used in a certain oilfield of China and the determined oilfield in-situ stresses is more accurate than that based on one single method.
基金This study was supported by the National Natural Science Foundation of China(81072714)the Natural Science Foundation of Fujian Province,China(No.2017J01545)。
文摘Objective:To establish a simple and efficient culture method of primary rabbit brain microvascular endothelial cells,provide important carriers and tool cells for the research of related cerebrovascular diseases.Methods:The cerebral cortexes of rabbits were collected aseptic and inoculated after cutting,passing through cell sieve,bovine serum albumin density gradient centrifugation,typeⅡcollagenase digestion,finally inoculated and cultured.The cultured cells were identified by cell morphological observation and angiogenesis experiment.Results:Under the inverted microscope,the cells were short fusiform or polygonal,and grew in clusters and adhere to the wall.After the cells were densely fused,they would be in a typical monolayer flat,“pebbled"mosaic arrangement.Tube formation test had the ability to form tubes structure.Conclusion:This method can successfully separate and cultivate primary rabbit brain microvascular endothelial cells.
文摘If tests are to provide an accurate measure of learners’ language abilities, examiners must minimize the influence of intervening factors such as response format. This article is to investigate the effects of two test formats on Chinese EFL learners' performance in reading tests. The findings confirm that test-takers' performance on reading is significantly affected by test formats and language level. All groups perform better on MCQ (Multiple Choice Questions) than SAQ (Short Answer Questions). Both test format and language proficiency level have main effect but they do not have interactive effect. By paying more attention to these factors examiners will enhance the validity of their tests.
