Musab Khudiri - Academia.edu (original) (raw)
Papers by Musab Khudiri
SPE Intelligent Energy International, 2012
When implementing an intelligent oilfield strategy it is tempting to focus on smart technology: a... more When implementing an intelligent oilfield strategy it is tempting to focus on smart technology: advanced applications, novel instrumentation and collaborative environments. The data architecture is often overlooked. As deployments increase, it is important to review the industry data foundation and future direction. WITSML version 1.4.1 is here and takes several bold steps to provide a robust, real-time foundation for data exchange and preservation. This version, the product of over two years of collaborative work by participants from oil companies, service companies and technology providers, is poised to be the keystone of the intelligent oilfield data architecture for wellsite communications. WITSML 1.4.1 is simpler, more efficient and better defined than previous versions. It addresses several problems that hindered earlier versions by clearly specifying API behaviour and resolving ambiguities. It is also more prescriptive, which makes greater demands on software vendors but assu...
Diocèses en guerre (1914-1918)
El analisis del financiamiento de la educacion en America Latina plantea algunos de los problemas... more El analisis del financiamiento de la educacion en America Latina plantea algunos de los problemas basicos de la crisis global y de las perspectivas de desarrollo de la region. No se trata -como en los paises centrales- de una situacion estable, en la que ya estan decididas las cuestiones fundamentales y en donde hay que optar por la asignacion de pequenos porcentajes de los recursos totales para uno u otro fin. En el caso de America Latina esta por definirse el marco conceptual del financiamiento, que dependera del estilo de desarrollo que se adopte. En el caso especifico de la educacion, debera determinarse como se insertara en el contexto social y economico global, y, en especial, cual sera la estructura del gasto segun los tipos de ensenanza que se desee privilegiar, asi como los recursos que se le asignaran, dados la estructura institucional, el sistema fiscal y los agentes sociales comprometidos. En este trabajo se comenzara por plantear el asunto de los estilos de desarrollo y...
Journal of Plant Protection and Pathology, 2019
Experiments were carried out in the experimental farm of Dokhmes EL-Mahlla EL-kobra,Grbea Governo... more Experiments were carried out in the experimental farm of Dokhmes EL-Mahlla EL-kobra,Grbea Governorate and another farm of Abosken village,Alhamol,kafr E-LSheikh Governorate during two successive seasons,2014 and 2015 to study the effect of planting dates on the main predators inhabiting five different maize varieties .The results showed that the delayed planting dates in August for the different varieties of maize crop had an effect on the presence of the largest number of predators from early planting dates in April and June during the two seasons of investigation 2014and 2015. The statistical analysis revealed that, highly significant difference in the number of the predators in the planting dates during both seasons. This study recommends that the cultivation date in August of the five defferent varieties recorded the highest number of predator insects and therefore should not use insecticides in this planting date so as not to destroy the insect predators.
SEG Technical Program Expanded Abstracts 2018, 2018
SPE Kingdom of Saudi Arabia Annual Technical Symposium and Exhibition, 2017
Wellbore friction, torque, and drag between the drill string and wellbore walls are generally cri... more Wellbore friction, torque, and drag between the drill string and wellbore walls are generally critical issues which limit the drilling industry to go beyond a certain angle and depth in highly deviated, horizontal and extended reach wells. It may result in complex drilling problems like stuck pipe, hole deviation, borehole instability and non-homogenous formations problems leading to increased non-productive time. An analytical model being used to estimate the influence of drilling assembly friction against the well bore profile which provides an understanding of the downhole conditions as well as in realizing the effect of its underlying parameters. This leads the E&P companies to use cost-effective solutions to predict and mitigate the issues in a timely manner to optimize drilling operations constituting huge potential cost saving. Considering the drilling operations in Saudi Arabia, a web-based, user-friendly and customizable solution was provided to drilling engineers and rig f...
SPE Kingdom of Saudi Arabia Annual Technical Symposium and Exhibition, 2017
Remote Casing Control (RCC) is an initiative of the Wellsite Geology Division with the support of... more Remote Casing Control (RCC) is an initiative of the Wellsite Geology Division with the support of Aramcolink. The aim of the RCC team is to provide 24/7 geological support about casing points remotely. Real-time data transmission and the advanced correlation tool are the basic requirements to achieve the end objective of picking the formation tops and casing points remotely. This paper describes the case study that illustrates the great impact of utilization of real-time data transmission and advanced real-time tools to pick casing points and formation tops remotely. The RCC team monitors the active well operation remotely with the help of real-time data streamed by Aramcolink. Moreover, Aramcolink has developed a logic/algorithm to calculate Drill Time from the streamed realtime data. Additionally, the mud logging unit can upload and share the lithology data RCC through the Aramcolink portal. This real-time data is being displayed/exported and downloaded from the Aramcolink viewer....
SPE Middle East Oil & Gas Show and Conference, 2017
In the context of current oil price volatility, every operator is trying to apply technologies to... more In the context of current oil price volatility, every operator is trying to apply technologies to reduce the cost of the drilling phase of their horizontal operations, whereas the interpretation application holds a vast portion of success rate in geosteering.Making geosteering functions more important to achieve the optimum production target. The advancement on the utilization of real time data and modeling data in various systems are introducing more critical operationaldecisions based on these systems. The new virtual geosteering system allows moving from complex multiple systems to a real time data solution with advance geological interpretation that supports a highly available collaborative virtual working environment for geoscientist and engineers during operations. A virtual geosteering system makes data available in a customized cross-section visualization, where it can be paired with real-time measurements while drilling and logging while drilling (LWD) information. This pap...
SPE Heavy Oil Conference and Exhibition, 2016
Long years of experience in the field and sometimes in the lab are required to develop consultant... more Long years of experience in the field and sometimes in the lab are required to develop consultants, Saudi ARAMCO is currently looking into the establishment of a new method to develop a drilling expert system that can be used as a training tool for young engineers or as a consultation system in various drilling engineering concepts such as well control, underbalanced drilling, drilling fluids, completion, and cementing practices. This method is done by proposing a set of guidelines for the optimal drilling operations in different focus areas, by integrating current best practices through a decision-making system based on Artificial Bayesian Intelligence. Optimum practices collected from literature review and experts’ opinions, are integrated into a Bayesian Network BN to simulate likely scenarios of its use that will honor efficient practices when dictated by varying certain parameters. The advantage of the artificial Bayesian intelligence method is that it can be updated easily whe...
Day 1 Mon, September 26, 2016, 2016
After the setup of a real-time drilling data feed from the Rig site to the operations center, the... more After the setup of a real-time drilling data feed from the Rig site to the operations center, the obvious question is - How good is the data that is being streamed? Real-Time rig sensor data could be an effective input for drilling optimization, However, the confidence in the results of these analysis or interpretations is directly associated to the trustworthiness of the data acquired. Measuring the quality of the data has been a difficult issue for many years. This paper shows the approach used by a large oil & gas operator to measure the quality of the information received from the rig providers, which is obtained from the sensors installed on every rig. The Real Time Data Quality is measured by analyzing six different parameters: completeness, uniformity, sensibility, resolution, structure and format. The combination of these six indexes provides a deep understanding of the level of the quality of the data received, as well as the elements to be improved. Various KPIs including ...
Frontiers in Neuroscience, 2015
Estimating cognitive or affective state from neurophysiological signals and designing application... more Estimating cognitive or affective state from neurophysiological signals and designing applications that make use of this information requires expertise in many disciplines such as neurophysiology, machine learning, experimental psychology, and human factors. This makes it difficult to perform research that is strong in all its aspects as well as to judge a study or application on its merits. On the occasion of the special topic "Using neurophysiological signals that reflect cognitive or affective state" we here summarize often occurring pitfalls and recommendations on how to avoid them, both for authors (researchers) and readers. They relate to defining the state of interest, the neurophysiological processes that are expected to be involved in the state of interest, confounding factors, inadvertently "cheating" with classification analyses, insight on what underlies successful state estimation, and finally, the added value of neurophysiological measures in the context of an application. We hope that this paper will support the community in producing high quality studies and well-validated, useful applications.
SPE Intelligent Energy International, 2012
When implementing an intelligent oilfield strategy it is tempting to focus on smart technology: a... more When implementing an intelligent oilfield strategy it is tempting to focus on smart technology: advanced applications, novel instrumentation and collaborative environments. The data architecture is often overlooked. As deployments increase, it is important to review the industry data foundation and future direction. WITSML version 1.4.1 is here and takes several bold steps to provide a robust, real-time foundation for data exchange and preservation. This version, the product of over two years of collaborative work by participants from oil companies, service companies and technology providers, is poised to be the keystone of the intelligent oilfield data architecture for wellsite communications. WITSML 1.4.1 is simpler, more efficient and better defined than previous versions. It addresses several problems that hindered earlier versions by clearly specifying API behaviour and resolving ambiguities. It is also more prescriptive, which makes greater demands on software vendors but assu...
SPE Saudi Arabia Section Technical Symposium and Exhibition, 2012
This paper describes the upstream data standards that Saudi Aramco has recently implemented for D... more This paper describes the upstream data standards that Saudi Aramco has recently implemented for Drilling and is in progress to implement them for other areas such as Production and Reservoir Characterization. These standards enable us to make wider use of our monitoring and collaboration centers through a common approach. It also allows us to leverage the evolving WITSML, PRODML and RESQML standards more effectively in our upstream operations. Saudi Aramco relies on many service organizations to deliver the generated data which requires common and standard data classification when exporting data from source A then importing to destination B. Applying a common approach to information access on a global basis has enabled us to streamline our operations and make wider use of emerging analysis, monitoring and collaboration technologies. Real-time technologies have been utilized to capture, monitor and analyze operational data from well sites so that critical decisions can be made in rea...
Transfusion, 2004
recent editorial in Transfusion reviewed the fact that it has become standard practice to assess ... more recent editorial in Transfusion reviewed the fact that it has become standard practice to assess the viability of RBCs and PLTs after storage or some other manipulation by labeling them with a radioisotope, generally 51 chromium or 111 indium, and returning them to the normal donor so that the percentage recovery and in vivo survival can be measured. 1 For RBCs, a “standard for approval” by the FDA of 75 percent for mean in vivo recovery at 24 hours after infusion has been accepted since 1982 after being put in place by the Division of Hematology at the FDA (J. Vostal, personal communication, 2002). Coupled with this is a requirement that the mean – 2 standard errors of the mean exceed 70 percent. After the first 24 hours, radioactivity declines at approximately 1 to 3 percent per day, but no standard has been set for survival after 24 hours. Having said this, the RBC standards have not been written down in a definitive fashion. Further, the editorial indicated that the situation is different for PLTs in that there is not even a generally accepted “standard for approval,” let alone any proposals committed to writing. Many innovations in PLT therapy are emerging for regulatory bodies, transfusion medicine specialists, and clinicians to consider, such as PLT additive solutions, pathogen reduction technologies, extension of storage, and combinations of these. We need and our patients deserve explicit standards to which these innovations can be compared. Here, proposals for such standards will be offered to stimulate discussion. We believe that the discussion will benefit from an historical review, which will extend back over 40 years. Until the 1990s, the majority of PLT-labeling studies were carried out with PLT concentrates (PC) derived from PLT-rich plasma (PRP), which, in turn, was derived from A donations of whole blood. Aster and Jandl 2 were the first to report the successful labeling and transfusion of PLTs obtained from blood anticoagulated with citrate. In normal donors in this study, the in vivo recovery of fresh, labeled PLTs did not average 100 percent as it would with RBCs, but rather 62 percent (range, 50-80%). With external organ scanning, there was a great deal of excess radioactivity over the spleen. Subsequent studies showed that patients with large spleens had unusually low in vivo recoveries (average, 23%) and that patients who had had a splenectomy had in vivo recoveries approaching 100 percent (average, 91%). 3 This data lead to the concept that, in normal individuals, the total body PLT mass is distributed with approximately two-thirds in the circulation and one-third in a pool in the spleen in excess of what would be predicted by the splenic blood volume. Because the circulating and splenic pools are in free interchange, the expected average in vivo recovery of fresh PLTs is 60 to 70 percent. The percentage of the body’s PLTs residing in the spleen appears to vary substantially among normal individuals. 4 There are several potential explanations for this variability. First, splenic volume varies widely in normal individuals (60-200 mL) 5 and splenic pool size correlates with splenic volume. 6 Furthermore, in normal individuals, splenic pool size varies inversely with the peripheral PLT count. 7 Finally, in calculating percentage recovery during labeling studies, the blood volume is estimated from the subject’s height and weight and is not directly measured. In an individual subject, this could lead to a consistent bias toward a low or high recovery. Furthermore, it has been reported that in vivo recovery may vary in the same individual at different times. 8 It is important to consider this variability in the size of the splenic pool in discussions of proposed standards. Our laboratory used methods very similar to those of Aster and Jandl 9 to study storage of PRP. The mean in vivo recovery for fresh PLTs was 69 percent, consistent with the findings of Aster and Jandl. 2 The range of recoveries for fresh PLTs in normal individuals was 40 to 80 percent. 9,10
SPE Intelligent Energy International, 2012
When implementing an intelligent oilfield strategy it is tempting to focus on smart technology: a... more When implementing an intelligent oilfield strategy it is tempting to focus on smart technology: advanced applications, novel instrumentation and collaborative environments. The data architecture is often overlooked. As deployments increase, it is important to review the industry data foundation and future direction. WITSML version 1.4.1 is here and takes several bold steps to provide a robust, real-time foundation for data exchange and preservation. This version, the product of over two years of collaborative work by participants from oil companies, service companies and technology providers, is poised to be the keystone of the intelligent oilfield data architecture for wellsite communications. WITSML 1.4.1 is simpler, more efficient and better defined than previous versions. It addresses several problems that hindered earlier versions by clearly specifying API behaviour and resolving ambiguities. It is also more prescriptive, which makes greater demands on software vendors but assu...
Diocèses en guerre (1914-1918)
El analisis del financiamiento de la educacion en America Latina plantea algunos de los problemas... more El analisis del financiamiento de la educacion en America Latina plantea algunos de los problemas basicos de la crisis global y de las perspectivas de desarrollo de la region. No se trata -como en los paises centrales- de una situacion estable, en la que ya estan decididas las cuestiones fundamentales y en donde hay que optar por la asignacion de pequenos porcentajes de los recursos totales para uno u otro fin. En el caso de America Latina esta por definirse el marco conceptual del financiamiento, que dependera del estilo de desarrollo que se adopte. En el caso especifico de la educacion, debera determinarse como se insertara en el contexto social y economico global, y, en especial, cual sera la estructura del gasto segun los tipos de ensenanza que se desee privilegiar, asi como los recursos que se le asignaran, dados la estructura institucional, el sistema fiscal y los agentes sociales comprometidos. En este trabajo se comenzara por plantear el asunto de los estilos de desarrollo y...
Journal of Plant Protection and Pathology, 2019
Experiments were carried out in the experimental farm of Dokhmes EL-Mahlla EL-kobra,Grbea Governo... more Experiments were carried out in the experimental farm of Dokhmes EL-Mahlla EL-kobra,Grbea Governorate and another farm of Abosken village,Alhamol,kafr E-LSheikh Governorate during two successive seasons,2014 and 2015 to study the effect of planting dates on the main predators inhabiting five different maize varieties .The results showed that the delayed planting dates in August for the different varieties of maize crop had an effect on the presence of the largest number of predators from early planting dates in April and June during the two seasons of investigation 2014and 2015. The statistical analysis revealed that, highly significant difference in the number of the predators in the planting dates during both seasons. This study recommends that the cultivation date in August of the five defferent varieties recorded the highest number of predator insects and therefore should not use insecticides in this planting date so as not to destroy the insect predators.
SEG Technical Program Expanded Abstracts 2018, 2018
SPE Kingdom of Saudi Arabia Annual Technical Symposium and Exhibition, 2017
Wellbore friction, torque, and drag between the drill string and wellbore walls are generally cri... more Wellbore friction, torque, and drag between the drill string and wellbore walls are generally critical issues which limit the drilling industry to go beyond a certain angle and depth in highly deviated, horizontal and extended reach wells. It may result in complex drilling problems like stuck pipe, hole deviation, borehole instability and non-homogenous formations problems leading to increased non-productive time. An analytical model being used to estimate the influence of drilling assembly friction against the well bore profile which provides an understanding of the downhole conditions as well as in realizing the effect of its underlying parameters. This leads the E&P companies to use cost-effective solutions to predict and mitigate the issues in a timely manner to optimize drilling operations constituting huge potential cost saving. Considering the drilling operations in Saudi Arabia, a web-based, user-friendly and customizable solution was provided to drilling engineers and rig f...
SPE Kingdom of Saudi Arabia Annual Technical Symposium and Exhibition, 2017
Remote Casing Control (RCC) is an initiative of the Wellsite Geology Division with the support of... more Remote Casing Control (RCC) is an initiative of the Wellsite Geology Division with the support of Aramcolink. The aim of the RCC team is to provide 24/7 geological support about casing points remotely. Real-time data transmission and the advanced correlation tool are the basic requirements to achieve the end objective of picking the formation tops and casing points remotely. This paper describes the case study that illustrates the great impact of utilization of real-time data transmission and advanced real-time tools to pick casing points and formation tops remotely. The RCC team monitors the active well operation remotely with the help of real-time data streamed by Aramcolink. Moreover, Aramcolink has developed a logic/algorithm to calculate Drill Time from the streamed realtime data. Additionally, the mud logging unit can upload and share the lithology data RCC through the Aramcolink portal. This real-time data is being displayed/exported and downloaded from the Aramcolink viewer....
SPE Middle East Oil & Gas Show and Conference, 2017
In the context of current oil price volatility, every operator is trying to apply technologies to... more In the context of current oil price volatility, every operator is trying to apply technologies to reduce the cost of the drilling phase of their horizontal operations, whereas the interpretation application holds a vast portion of success rate in geosteering.Making geosteering functions more important to achieve the optimum production target. The advancement on the utilization of real time data and modeling data in various systems are introducing more critical operationaldecisions based on these systems. The new virtual geosteering system allows moving from complex multiple systems to a real time data solution with advance geological interpretation that supports a highly available collaborative virtual working environment for geoscientist and engineers during operations. A virtual geosteering system makes data available in a customized cross-section visualization, where it can be paired with real-time measurements while drilling and logging while drilling (LWD) information. This pap...
SPE Heavy Oil Conference and Exhibition, 2016
Long years of experience in the field and sometimes in the lab are required to develop consultant... more Long years of experience in the field and sometimes in the lab are required to develop consultants, Saudi ARAMCO is currently looking into the establishment of a new method to develop a drilling expert system that can be used as a training tool for young engineers or as a consultation system in various drilling engineering concepts such as well control, underbalanced drilling, drilling fluids, completion, and cementing practices. This method is done by proposing a set of guidelines for the optimal drilling operations in different focus areas, by integrating current best practices through a decision-making system based on Artificial Bayesian Intelligence. Optimum practices collected from literature review and experts’ opinions, are integrated into a Bayesian Network BN to simulate likely scenarios of its use that will honor efficient practices when dictated by varying certain parameters. The advantage of the artificial Bayesian intelligence method is that it can be updated easily whe...
Day 1 Mon, September 26, 2016, 2016
After the setup of a real-time drilling data feed from the Rig site to the operations center, the... more After the setup of a real-time drilling data feed from the Rig site to the operations center, the obvious question is - How good is the data that is being streamed? Real-Time rig sensor data could be an effective input for drilling optimization, However, the confidence in the results of these analysis or interpretations is directly associated to the trustworthiness of the data acquired. Measuring the quality of the data has been a difficult issue for many years. This paper shows the approach used by a large oil & gas operator to measure the quality of the information received from the rig providers, which is obtained from the sensors installed on every rig. The Real Time Data Quality is measured by analyzing six different parameters: completeness, uniformity, sensibility, resolution, structure and format. The combination of these six indexes provides a deep understanding of the level of the quality of the data received, as well as the elements to be improved. Various KPIs including ...
Frontiers in Neuroscience, 2015
Estimating cognitive or affective state from neurophysiological signals and designing application... more Estimating cognitive or affective state from neurophysiological signals and designing applications that make use of this information requires expertise in many disciplines such as neurophysiology, machine learning, experimental psychology, and human factors. This makes it difficult to perform research that is strong in all its aspects as well as to judge a study or application on its merits. On the occasion of the special topic "Using neurophysiological signals that reflect cognitive or affective state" we here summarize often occurring pitfalls and recommendations on how to avoid them, both for authors (researchers) and readers. They relate to defining the state of interest, the neurophysiological processes that are expected to be involved in the state of interest, confounding factors, inadvertently "cheating" with classification analyses, insight on what underlies successful state estimation, and finally, the added value of neurophysiological measures in the context of an application. We hope that this paper will support the community in producing high quality studies and well-validated, useful applications.
SPE Intelligent Energy International, 2012
When implementing an intelligent oilfield strategy it is tempting to focus on smart technology: a... more When implementing an intelligent oilfield strategy it is tempting to focus on smart technology: advanced applications, novel instrumentation and collaborative environments. The data architecture is often overlooked. As deployments increase, it is important to review the industry data foundation and future direction. WITSML version 1.4.1 is here and takes several bold steps to provide a robust, real-time foundation for data exchange and preservation. This version, the product of over two years of collaborative work by participants from oil companies, service companies and technology providers, is poised to be the keystone of the intelligent oilfield data architecture for wellsite communications. WITSML 1.4.1 is simpler, more efficient and better defined than previous versions. It addresses several problems that hindered earlier versions by clearly specifying API behaviour and resolving ambiguities. It is also more prescriptive, which makes greater demands on software vendors but assu...
SPE Saudi Arabia Section Technical Symposium and Exhibition, 2012
This paper describes the upstream data standards that Saudi Aramco has recently implemented for D... more This paper describes the upstream data standards that Saudi Aramco has recently implemented for Drilling and is in progress to implement them for other areas such as Production and Reservoir Characterization. These standards enable us to make wider use of our monitoring and collaboration centers through a common approach. It also allows us to leverage the evolving WITSML, PRODML and RESQML standards more effectively in our upstream operations. Saudi Aramco relies on many service organizations to deliver the generated data which requires common and standard data classification when exporting data from source A then importing to destination B. Applying a common approach to information access on a global basis has enabled us to streamline our operations and make wider use of emerging analysis, monitoring and collaboration technologies. Real-time technologies have been utilized to capture, monitor and analyze operational data from well sites so that critical decisions can be made in rea...
Transfusion, 2004
recent editorial in Transfusion reviewed the fact that it has become standard practice to assess ... more recent editorial in Transfusion reviewed the fact that it has become standard practice to assess the viability of RBCs and PLTs after storage or some other manipulation by labeling them with a radioisotope, generally 51 chromium or 111 indium, and returning them to the normal donor so that the percentage recovery and in vivo survival can be measured. 1 For RBCs, a “standard for approval” by the FDA of 75 percent for mean in vivo recovery at 24 hours after infusion has been accepted since 1982 after being put in place by the Division of Hematology at the FDA (J. Vostal, personal communication, 2002). Coupled with this is a requirement that the mean – 2 standard errors of the mean exceed 70 percent. After the first 24 hours, radioactivity declines at approximately 1 to 3 percent per day, but no standard has been set for survival after 24 hours. Having said this, the RBC standards have not been written down in a definitive fashion. Further, the editorial indicated that the situation is different for PLTs in that there is not even a generally accepted “standard for approval,” let alone any proposals committed to writing. Many innovations in PLT therapy are emerging for regulatory bodies, transfusion medicine specialists, and clinicians to consider, such as PLT additive solutions, pathogen reduction technologies, extension of storage, and combinations of these. We need and our patients deserve explicit standards to which these innovations can be compared. Here, proposals for such standards will be offered to stimulate discussion. We believe that the discussion will benefit from an historical review, which will extend back over 40 years. Until the 1990s, the majority of PLT-labeling studies were carried out with PLT concentrates (PC) derived from PLT-rich plasma (PRP), which, in turn, was derived from A donations of whole blood. Aster and Jandl 2 were the first to report the successful labeling and transfusion of PLTs obtained from blood anticoagulated with citrate. In normal donors in this study, the in vivo recovery of fresh, labeled PLTs did not average 100 percent as it would with RBCs, but rather 62 percent (range, 50-80%). With external organ scanning, there was a great deal of excess radioactivity over the spleen. Subsequent studies showed that patients with large spleens had unusually low in vivo recoveries (average, 23%) and that patients who had had a splenectomy had in vivo recoveries approaching 100 percent (average, 91%). 3 This data lead to the concept that, in normal individuals, the total body PLT mass is distributed with approximately two-thirds in the circulation and one-third in a pool in the spleen in excess of what would be predicted by the splenic blood volume. Because the circulating and splenic pools are in free interchange, the expected average in vivo recovery of fresh PLTs is 60 to 70 percent. The percentage of the body’s PLTs residing in the spleen appears to vary substantially among normal individuals. 4 There are several potential explanations for this variability. First, splenic volume varies widely in normal individuals (60-200 mL) 5 and splenic pool size correlates with splenic volume. 6 Furthermore, in normal individuals, splenic pool size varies inversely with the peripheral PLT count. 7 Finally, in calculating percentage recovery during labeling studies, the blood volume is estimated from the subject’s height and weight and is not directly measured. In an individual subject, this could lead to a consistent bias toward a low or high recovery. Furthermore, it has been reported that in vivo recovery may vary in the same individual at different times. 8 It is important to consider this variability in the size of the splenic pool in discussions of proposed standards. Our laboratory used methods very similar to those of Aster and Jandl 9 to study storage of PRP. The mean in vivo recovery for fresh PLTs was 69 percent, consistent with the findings of Aster and Jandl. 2 The range of recoveries for fresh PLTs in normal individuals was 40 to 80 percent. 9,10