These data suggest that FrzB-2 may play a role in apoptosis and that the expression of this protein may be important in the pathogenesis of human OA.
A joint-industry project (JIP) from 2005 through 2009 involved acquiring, analyzing, and documenting more than 100 subsalt wells in the Gulf of Mexico (GOM), from shelf to deepwater. The result of this unique study culminated in the compilation of a large and comprehensive database of pertinent petrophysical, geophysical, and drilling data. This database was used to develop a set of suggested best practices for pore-pressure estimation below and around salt bodies. An analysis of the wells in the subsalt JIP indicated that the majority (64%) of the wells studied demonstrated evidence of a subsalt gouge or rubble zone. Sufficient data for this analysis was obtained from 87 JIP wells. Statistical analysis of this large database allowed a wide range of correlations to be established for the subsalt rubble-zone occurrence with salt body structural and geological features. An early diagnostic of rubble zones using logging while drilling (LWD) tools can trigger certain drilling practices to be employed. This paper presents the diagnostic criteria for a subsalt rubble zone and several other confirmatory criteria. The diagnostic identification for a subsalt rubble zone is small-scale discordance between the gamma ray and the resistivity log in the interval immediately below the salt. The relationship between rubble-zone occurrence and salinity changes is discussed.Drilling subsalt rubble zones can be challenging. This paper documents current industry methods for drilling subsalt wells based on the analysis of multiple sources of data. In addition to the subsalt database, data was compiled from an industry questionnaire designed to capture current practices for drilling subsalt wells, a survey and reviews on subsalt drilling-related published literature, and personal interviews with industry professionals. This paper focuses on the following key subsalt (with and without a rubble zone) drilling issues of interest to wellconstruction professionals: the drilling window, casing setting, loss of circulation, wellbore stability, mud-weight scenarios, and leakoff tests. Highlights of each of the aforementioned drilling issues are presented along with well examples.
Metachronal beating of cilia of epithelial surfaces of most respiratory airways moves the overlying mucous layer in a caudal direction. The molecular mechanisms controlling ciliary beat remain largely unknown. Calcium, an element in its cationic form, is ubiquitous in biological functions and its concentration is critical for ciliary beating. Calmodulin, a calciumbinding protein which regulates the activity of many enzymes and cellular processes, may regulate ciliary beating by controlling enzymes responsible for mechanochemical movement between adjacent peripheral microtubule doublets composing the ciliary axoneme. As a first step in describing a calmodulin-related controlling mechanism for ciliary beating, calmodulin was localized in the ciliated cells lining the respiratory tracts of hamsters by electron microscopy, using an indirect immunoperoxidase technique with anticalmodulin antibodies as the molecular probe. Thin-sections revealed calmodulin located on microtubules and dynein arms of the ciliary shaft, basal body, apical cytoskeletal microtubules, and plasma membranes in specimens fixed with 1 mM Ca +2. Specimens fixed with less Ca ÷2 (1 #M), Mn +2, Mg +2, and EGTA showed a diffuse pattern of calmodulin with loci of greatest densities on basal body microtubule triplets. Demembranated specimens showed a less specific localization on axonemal microtubules but only on cells fixed with Ca +2. Calmodulin, by binding calcium, may function in ciliary beating in the respiratory tract of mammals either directly or indirectly through its effects on the energy-producing enzymes and by control of Ca ÷2 flux through plasma membranes.The epithelial lining of respiratory airways contains a large number of ciliatcd cells responsible for mucous clearance mediated by metachronai ciliary beating. The cilia on the surface of these cells are anchored into the apical cytoplasm by basal bodies, centriole counterparts (5, 26). Microtubules and microfilaments form an integrated system linking the ciliary axoneme and basal body to the cytoskeleton (8).The mechanism(s) controlling ciliary beat initiation, frequency, and synchronization is unknown, but changes in beat pattern of cilia and flagella are due to calcium ion concentrations, e.g., ciliary reversal in Paramecium (4) and Tetrahymena (29), ciliary arrest in molluscan gill (24), flagellar wave form change in Chlamydomonas (25), reversal of the flagellar wave propagation in Crithidia (13), asymmetrical (2) and intermittent (6, 7) flagellar beating in sea urchin sperm, mammalian ciliary beat frequency change (3) and activation (21) and in vitro (14). Ohnishi et al. (23) suggested that calcium ion effect may be a two-step phenomenon: (a) an influx of Ca +2 into the cilia or flagella and (b) a specific effect on the motile apparatus of the cilia or flagella. Calmodulin may be a specific intermediate target molecule for the calcium effects on cilia and flagella described above.Calmodulin--a small, acidic calcium-binding protein that modulates numerous enzymatic reactio...
Predicting pore pressure in subsalt sediment has been, and continues to be, challenging for the well planner. Subsalt sediments belong to a wide range of depositional settings and have been affected by complex geologic and tectonic events, making it difficult to accurately predict pore pressure. A joint industry project (JIP) acquired, analyzed, and documented more than 100 subsalt wells in the Gulf of Mexico from shelf to deepwater (2007-2009). The result of this unique and major study culminated in an unprecedented, comprehensive database, which includes geophysical, petrophysical, and drilling data. This database was used to develop best practices for pore-pressure estimation below salt. In this work, both conventional and unconventional pore-pressure prediction methods—including acoustic and resistivity methods—were applied, tested, ranked, and evaluated against known pore-pressure indicators, such as, MDT/RFT, kicks, and gas shows. The existence, thickness, and effect of a gouge (rubble) zone adjacent to the salt body was recognized by a set of criteria, and its potential effects on pore pressure and fracture gradient in the vicinity of salt have been addressed. This paper addresses the different pore-pressure regimes present in subsalt sediments, pore pressure variations in different deepwater settings, and the key findings from applying more than 10 different pore-pressure prediction methods. Variations of compressional/shear velocity pore-pressure prediction methods are briefly addressed. The goal of this work is to automate the pore-prediction methods to make it less " user dependent" and to base it on rock physics and geologic settings. Resistivity-based pore-pressure prediction methods are reviewed with emphasis on salinity normalization to negate salinity variations around a salt body. With more than 95 wells tested with these different methods, pore-pressure prediction methodologies have been proven successful, with an average error of less than 0.5 ppg. Introduction The drilling of subsalt sediments is often challenged by the presence of a narrow drilling window, as well as wellbore instability in rubbelized sediments. The operators attempt to exit the salt with a good drilling strategy based on the available data from pre-drill to real-time data. The pre-drill pore-pressure estimation is marred by the poor quality of seismic velocity estimation below salt. If the velocity data becomes more definitive and accurate in the light of acquisition of a VSP log, which may be run just prior to exiting the salt, the need still exists today to use a robust pore-pressure estimation model. The subsalt joint-industry project was active during 2006 and 2007 with eleven active participants, including major operators and service companies with the objective of developing best practices for subsalt pore-pressure prediction. A total of 107 subsalt wells were analyzed in this project. These wells provided the database for the other studies that were done for this project: the Vp/Vs, resistivity normalization, subsalt gouge-zone analysis, and others. Pore pressure for all of the wells was estimated from petrophysical analysis of log data. A number of different pressure-analysis models were tested on each of the wells. The results were compared to variations in geology and region to attempt to derive correlations between subsalt pressure and geographic location. The additional project objectives included:Determining the state-of-the-art in subsalt planning and drilling,Acquiring and analyzing data from 50-100 subsalt wells and document pressure and drilling data,Examining seismic for those locations for structural effects on pore pressure and for imaging at salt entry/exit,Building a set of geologic models and examining the influence on seismic imaging,Developing and documenting best practices.
Unconventional oil and gas assets, specifically shale, have captured a tremendous amount of attention in the petroleum industry as new technologies prove that these ultra low permeability reservoirs can achieve economic success in today's business environment.Transferring these technologies to new areas where different business environments exist and where, in many cases, the potential plays are not yet well understood requires that understanding of the geology and the reservoir catch up to the engineering solutions for drilling and completing shale wells. This is necessary both for minimizing discovery costs and accelerating economic development in these new environments.There have been many studies focused on understanding production from shale assets, but these are often centered on a particular region and provide solutions that are very specific and not easily transferred to new regions without significant effort and risk. A detailed understanding of these complex source rock petroleum systems is required to identify specific attributes within a given play that indicate the ability to achieve economic success. This paper emphasizes the need create a very close and collaborative environment that brings together several key disciplines including basin modeling, geology, geophysics, geomechanics, and petrophysics along with reservoir, completions, and drilling engineering. Making intelligent decisions in these developments requires a depth of knowledge that exceeds any one of these disciplines, so this paper looks at several key areas that need to be brought together to accelerate the learning curve and achieve economic success. Tools and processes designed specifically for complex source rock petroleum systems are discussed. These demonstrate the benefits from an improved understanding of the complete system. These will enable improved reservoir modeling, completion design tools, and ultimately enhanced field performance.
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