Well servicing structure

Standard Derricks 501. Load Capacities 506. Design Loadings 508. Design Specifications 511. Maintenance and Use of Drilling and Well Servicing Structures 515. Derrick Efficiency Factor 521. 

The API Standard 4F, First Edition, May 1, 1985, API Specifications for Drilling and Well Servicing Structures, was written to provide suitable steel structures for drilling and well servicing operations and to provide a uniform method of rating the structures for the petroleum industry. API Standard 4F supersedes API Standards 4A, 4D, and 4E thus, many structures in service today may not satisfy all of the requirements of API Standard 4F [2-5]. 

For modern derrick and mast designs, API Standard 4F is the authoritative source of information, and much of this section is extracted directly from this standard. Drilling and well servicing structures that meet the requirements of API Standard 4F are identified by a nameplate securely affixed to the structure in a conspicuous place. The nameplate markings convey at least the following information ... 

The manufacturer of structures that satisfy API Standard 4F must also furnish the purchaser with one set of instructions that covers operational features, block reeving diagram, and lubrication points for each drilling or well servicing structure. Instructions should include the raising and lowering of the mast and a facsimile of the API nameplate. 

Recommended Practice for Maintenance and Use of Drilling and Well Servicing Structures... 

The drilling and well servicing structure manufacturer has carefully designed and selected materials for his or her portable mast. The mast should perform satisfactorily within the stipulated load capacities and in accordance with the instructions. Every operator should study the instructions and be prepared for erecting, lowering, and using the mast. 

Maximum Load Rating Bases. The maximum load rating will be based on the design safety factor and the yield strength of the material. Crown block beams are an exception and shall be rated and tested in accordance with API Spec 4E Specification for Drilling and Well Servicing Structures. ... 

API Standard 4F, First Edition API Specification for Drilling and Well Servicing Structures," API, Dallas, May 1985. 

Ley General de Sanidad (Ministerio de Sanidad y Consumo, 1986). This is a general law that regulates most subjects health-related, including all health service structures and requirements for drug commercialization, as well as some of the pharmacist s functions as a healthcare provider. 

The means for fabricating apparently well-bonded structures has been discussed by the authors of the earlier chapters of this book. While we should have some confidence in following some of the best advice that can be offered, there is still no assurance without carefully planned test evaluations that long-term endurance service life has actually been achieved. 

Safety and serviceability can be easily achieved if there is no consideration of economic cost. However to satisfy today s culture, A WELL DESIGNED STRUCTURE SHOULD BE JUST SAFE, JUST SERVICEABLE AND BE OPTIMAL IN COST. Complete adherence to this optimality principle is seldom possible in practice, but health and safety cannot be sacrificed for the pursuit of commercialism. 

The suggested method is appropriately implemented at the practice. The cost and working hours of unit measurement of it is less than of any alternative method of destructive test and with respect to the authenticity inspection of Stress-Deformation the given method is inferior only to destructive testing. The method was successfully implemented while evaluation of service life of main pipe-lines sections and pressure vessels as well. Data of method and instrument are used as official data equally with ultrasonic, radiation, magnetic particles methods, adding them by the previously non available information about " fatigue " metalwork structure. 

The WLN was applied to indexing the Chemical Structure Index (CSI) at the Institute for Scientific Information (ISI) [13] and the Ituiex Chemicus Registry System (ICRS) as well as the Crossbow System of Imperial Chemical Industries (ICl). With the introduction of connection tables in the Chemical Abstracts Service (CAS) in 1965 and the advent of molecular editors in the 1970s, which directly produced connection tables, the WLN lost its importance. 

More than 10 000 databases exist that provide a small or large amount of data on various topics (including chemistry). The contents in databases are supplied by approximately 3500 database developers (e.g., the Chemical Abstracts Service, MDL Information Systems, etc.). Since there is a variety of topics from economics to science, as well as a variety of structures of the database, only some of the vendors (-2000) offer one or more databases as either local or as online databases (Figure 5-4) [4]. Usually, databases are provided by hosts that permit direct access to more than one database. The search occurs primarily through different individual soft-... 

The Web-based graphical user interface permits a choice from numerous criteria and the performance of rapid searches. This service, based on the chemistry information toolkit CACTVS, provides complex Boolean searches. Flexible substructure searches have also been implemented. Users can conduct 3D pharmacophore queries in up to 25 conformations pre-calculated for each compound. Numerous output formats as well as 2D and 3D visuaHzation options are supplied. It is possible to export search results in various forms and with choices for data contents in the exported files, for structure sets ranging in size from a single compound to the entire database. Additional information and down-loadable files (in various formats) can be obtained from this service. 

Factors that are important for the limitation of protected areas are the pipe network structure, degree of mesh, number of service pipes, type of pipe connections, quality of the pipe coating and availability of protection current as well as stray current effects. A protected area in a distribution network is shown in Fig. 10-11 with separate parts of the network (NT I to NT IV). Previous experience has shown that protected areas of 1 to 2 km with lengths of pipeline from 10 to 20 km are advantageous [30],... 

Designers must keep in mind that modem aircraft will likely be in service for thirty years and that repair of adhesive bonded structure will be inevitable. They must allow for reasonable disassembly of bonded stmcture for repair access as well as anticipate repair procedures that will not be unduly difficult for airline repair stations. 

External events are accident initiators that do not fit well into the central PSA structure used for "internal events." Some "external events" such as fire due to ignition of electrical wires, or flood from a ruptured service water pipe occur inside the plant. Others, such as earthquakes and tornados, occur outside of the plant. Either may cause failures in a plant like internal events. External initiators may cause multiple failures of independent equipment thereby preventing action of presumably redundant protection systems. For example, severe offsite flooding may fli 1 the pump room and disable cooling systems. An earthquake may impede evacuation of the nearby populace. These multiple effects must be considered in the analysis of the effects of external events. 

The component hardware data were well-based because they are derived from 22 years of records. It is also useful because of the structure and depth of the presentation for example, the Inclusion of data on pumps in different systems (emergency feedwater, condensate, service water). 

The final plant layout combines the various engineering considerations for soil conditions drainage railroad, truck and services access raw materials receiving waste materials removal climate effect on outdoor versus indoor operations and on types of structures prevailing wind direction for vent as well as climiatic moisture corrosion plant expansion and growth access to public, and many other general evaluation points. From these broad considerations the details are developed to suit the particular plant process and the combined effects of the location. 

Only a small amount of the metal used in underground service is present in the ground water zone. Such structures as well casings and under-river pipelines are surrounded by ground water. The corrosion conditions in such a situation are essentially those of an aqueous environment. 

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