Trees, Christmas

For the very first section of the borehole a base from which to commence drilling is required. In a land location this will be a cemented cellar in which a conductor or stove pipe will be piled prior to the rig moving in. The cellar will accommodate the Christmas tree (an arrangement of seals and valves), once the well has been completed and the rig has moved off location (Fig. 3.13)... 

The figure on the right shows the well with a simple well completion including a production tubing with packer, a series of surface safety valves called a Christmas tree, a subsurface safety valve (SSSV), a circulating sleeve, and a series of perforations through the casing. 

The ribbon machine employs a puff-and-blow method to make incandescent light bulb envelopes (1200/min), dashbulb envelopes (2000/min), Christmas tree ornaments, and the like (Fig. 15). For larger articles, the turret chain machine also uses the puff-and-blow method, but produces less cuUet and uses individual glass gobs rather than ribbon. 

For current consoHdation, the basic circuits, used at each of the multiple power take-off points, are stacked into a Christmas tree topology to form a single power take-off terminal pair. Scale-up of these devices to commercial sizes is not expected to be a problem, as standard electrical components are available for all sizes considered. A different type of consoHdation scheme developed (117), uses dc to ac converters to connect the individual electrodes to the consoHdation point. The current from each electrode can be individually controUed by the converter, which can either absorb energy from or deHver energy to the path between the electrode and the consoHdation point. This scheme offers the potential capabiHty of controlling the current level of each electrode pair. 

A sniallcr-diaiiieter pipe, called tubing, is then threaded together and inserted into the casing. If it is expected that oil or gas will flow to the surface via the pressure differential between the well bore and the formation, a wellhead is installed it is equipped with valves to control the flow of oil or gas from the well. The wellhead is known as a Christmas tree. If there is not sufficient pressure differential to cause the oil and the gas to flow naturally, pumping equipment is installed at the lower end of the tubing. 

Crops Oranges Lemons Bare ground Christmas trees Tomatoes Cauliflower Oranges Lemons Tomatoes Cauliflower... 

Assessments of risks associated with the use of chlorpyrifos insecticide products for workers have been made. The assessments are based on the results of field studies conducted in citrus groves, a Christmas tree farm, cauliflower and tomato fields, and greenhouses that utilized both passive dosimetry and biomonitoring techniques to determine exposure. The biomonitoring results likely provide the best estimate of absorbed dose of chlorpyrifos, and these have been compared to the acute and chronic no observed effect levels (NOELs) for chlorpyrifos. Standard margin-of-exposure (MOE) calculations using the geometric mean of the data are performed however, probability (Student s f-test) and distributional (Monte Carlo simulation) analyses are deemed to provide more realistic evaluations of exposure and risk to the exposed population. 

The produced oil or gas is connected to surface flowlines from the wellhead pumping unit or surface regulating valve assembly typically referred to as a Christmas tree but to its arrangement. The flowlines collect the oil or gas to local tank batteries or central production facilities for primary oil, water, and gas separation. The reliability of electrical submersible pumps (ESPs) has increased to the point where the submersible electrical pump is commonly used for the production of liquid hydrocarbons where artificial lift is required for production. 

Christmas Tree - An assembly of valves, gauges, and chokes mounted on a well casinghead to control the flow and pressure of oil or gas to a pipeline. 

Chondroitin 6-sulfate, 4 706 Chondroitin sulfates, 20 456 Chopped strand mat (CSM), 26 751 Chopper pumps, 21 78 Chop-stx number, for boron hydrides, 4 183 Chorinated trisodium phosphate, 4 52 Christmas tree module design, 15 835 Chromacity diagrams, 7 313-315 Chromaphores, 19 379 Chromate coatings, 9 827 Chromate conversion coatings, 16 218 Chromated copper arsenate, 3 276 ... 

Both TATP and HMTD have been applied by terrorist groups worldwide in the production of homemade detonators. TATP is, however, seen in more instances. Examples of improvised caps can be seen in Figure 3.10. The photograph gives an illustration of the standard paper detonators (in this case produced from yellow lined paper and Christmas tree bulbs) and also shows a variety produced from syringes. The detonators in the photograph were recovered in Amman, Jordan. 

A hydrocarbon structure can serve as a framework to which various heteroatoms can be attached. This is analogous to a Christmas tree serving as the scaffolding on which ornaments are hung. Just as the ornaments give character... 

When a platform is not a practical way to develop an offshore field, the operator may complete the well using a submerged production system, in which case, the Christmas tree and other wellhead equipment are installed on the sea bottom and pipelines are connected to carry off the petroleum, either to shore, to a nearby platform, or to a vessel or storage buoy moored in the area. Divers can be used to make the necessary connections. 

Fig. 22. Completed oil well showing the Iluw of oil into and up tile well Lo the pipeline connection at die Christmas tree. (American Petroleum Institute)...

---