Well years

Posted price of midcontinent crude oil at the well (yearly average). 

Although the QALY is the most commonly used health outcome summary measure, it is not the only one. Other conceptually equivalentoutcomes include years of healthy lifeiYHl), well years (WYs), health-adjusted person-years (HAPYs), and health-adjusted life expectancy (HALE). An alternative concept called healthy year equivalents (HYEs) has been proposed as theoretically superior to QALYs, but its practi-cai significance has been iimited. 

HIV/AIDS human immunodeficiency virus/acquired immunodeficiency syndrome HUI Health Utilities Index HYEs healthy-year equivalents ICC intraclass correlation coefficient KDQOL Kidney Disease Quality of Life instrument MCS mental component summary scale of the SF-36 MOS-HTV Medical Outcomes Study HIV Health Survey MOT Medical Outcomes Trust MSQOL Migraine Specific Quality of Life NHP Nottingham Health Profile PCS physical component summary scale of the SF-36 QALY quahty-adjusted hfe year QOL quahty of life QOLIE Quality of Life in Epilepsy QWB Quality of WeU-Being scale SF-36 MOS 36-Item Short-Form Health Survey SIP Sickness Impact Profile VAS visual analog scale WY well year YHL years of healthy life... 

With the introduction of new antipollution standards as well as limitations envisaged for the chemical composition of finished products, current refining flowsheets and especially those beyond the year 2000 will have to adapt to the new specifications using new processes. 

Initially new wells may still be brought on stream but the older wells start to decline. A constant production rate is maintained. This period is typically 2 to 5 years for an oil field, but longer for a gas field. 

An intermediate casing is usually set above the reservoir in order to protect the water bearing, hydrostatically pressured zones from influx of possibly overpressured hydrocarbons and to guarantee the integrity of the well bore above the objective zone. In mature fields where production has been ongoing for many years, the reservoir may show depletion pressures considerably lower than the hydrostatically pressured zones above. Casing and cementing operations are covered in section 3.6. 

Wells may be drilled at a constant angle to the target or dropped off to a lower angle through the reservoir section. To build, maintain or drop the deviation angle stabilisers are run in the bottom hole assembly (Fig. 3.15). A change in deviation used to require a round trip to change the position of those stabilisers in the bottom hole assembly. In recent years, adjustable, hydraulically activated stabilisers have been developed. The... 

Not surprisingly, costs are several times higher than conventional wells. Nevertheless, overall project economics may favour ERD over other development options. For example, BP developed the offshore part of the Wytch Farm Oilfield (which is located under Poole Harbour in Dorset, UK) from an onshore location. The wells targeted the reservoir at a vertical depth of 1,500 meters with a lateral displacement of over 8,000 meters (Fig. 3.20). The alternative was to build a drilling location on an artificial island in Poole Bay. ERD probably saved a considerable amount of money and advanced first oil by several years. 

In recent years a new approach to contracting has evolved and Is gaining rapid acceptance In the United Kingdom Continental Shelf (UKCS). The concept has become known as partnering and can be seen as a progression of the incentive contract. Whilst the previously described contractual arrangements are restricted to a single well project... 

The prediction of the size and permeability of the aquifer is usually difficult, since there is typically little data collected in the water column exploration and appraisal wells are usually targeted at locating oil. Hence the prediction of aquifer response often remains a major uncertainty during reservoir development planning. In order to see the reaction of an aquifer, it is necessary to produce from the oil column, and measure the response in terms of reservoir pressure and fluid contact movement use is made of the material balance technique to determine the contribution to pressure support made by the aquifer. Typically 5% of the STOMP must be produced to measure the response this may take a number of years. 

Drawdown and build-up surveys are typically performed once a production well has been completed, to establish the reservoir property of permeability (k), the well completion efficiency as denoted by its skin factor (S), and the well productivity index (PI). Unless the routine production tests indicate some unexpected change in the well s productivity, only SBHP surveys may be run, say once a year. A full drawdown and build-up survey would be run to establish the cause of unexplained changes in the well s productivity. 

The treatment of expenditures will be specified by the fiscal system set by the host government. A typical case would be to define expenditure on items whose useful life exceeds one year as capital expenditure (capex), such as costs of platforms, pipelines, wells. Items whose useful life is less than one year (e.g. chemicals, services, maintenance, overheads, insurance costs) would then be classed as operating expenditure (opex). 

If the original field development plan was not based on a 3-D seismic survey (which would be a commonly used tool for new fields nowadays), then it would now be normal practice to shoot a 3-D survey for development purposes. The survey would help to provide definition of the reservoir structure and continuity (faulting and the extension of reservoir sands), which is used to better locate the development wells. In some cases time-lapse 3-D seismic 4D surveys carried out a number of years apart, see Section 2) is used to track the displacement of fluids in the reservoir. 

Hydrocarbon-water contact movement in the reservoir may be determined from the open hole logs of new wells drilled after the beginning of production, or from a thermal decay time (TDT) log run in an existing cased production well. The TDT is able to differentiate between hydrocarbons and saline water by measuring the thermal decay time of neutrons pulsed into the formation from a source in the tool. By running the TDT tool in the same well at intervals of say one or two years (time lapse TDTs), the rate of movement of the hydrocarbon-water contact can be tracked. This is useful in determining the displacement in the reservoir, as well as the encroachment of an aquifer. 

The specific results of well over 1 year of continued monitoring will be discussed in a second paper. It is pointed out here that the AEBIL monitoring system installed in the power plant for the above monitoring purposes has efficiently and continuedly performed during this time interval, with no instrumentation reliability problems. 

Anumber of defects with manual inspection indications clarified by AUGUR 4.2 records have been accepted for further operation in 1996 with prescription of next year AUGUR 4 2 inspection. Based on two consecutive inspections (1996-97 years) comparative analysis of AUGUR 4.2 data was executed. It was shown that the flaw configurations, reproduced by AUGUR 4.2 are stable and the small differences are conditioned only by system thresholds of linear coordinate and signal amplitude as well as variations in local conditions of in-site inspection. 

In general, radioscopic X-ray inspection systems are used in the serial examination of industrial workpieces since they enable a flexible adjustment of the beam direction and of the inspection perspective as well as on-line viewing of the radioscopic image. In the past few years this economic and reliable method has become prevalent in weld inspection during the manufacturing process of pipes. The configuration of such radioscopic systems is schematically represented in fig. 1. 

Computerized Tomographic Imaging (CT), a well established method in medical diagnostics for 25 years now, also makes its arrival into non-destructive testing since the last decade. 

There is a trend in the last years to extend the application range of metal-ceramic tubes also to medium power portable equipment 160kV to 300kV portable systems are well known in the market. 

In the last years one can find a strong reorientation of most microscopical methods to study objects in natural (or adjustable) conditions without preparation. Microscopical visualization without vacuum and coating allows maintaining the natural specimen structure as well as examining its behavior under external influences (loading, chemical reactions, interaction with other solids, liquids, gases etc.)... 

The verifications can be performed by the user himself, with electronic measurement equipment described in this project. The consequences of the application of future European standard are very important since is established a mandatory verification of each particular flaw detector, at least once a year. Their verification is to be performed according to a well defined procedure of measurement, including acceptance criteria for each parameter. 

It should be pointed out, that one of the existing negative points with bad economical and social consequences is the appearance of false and counterfeit securities, documents, notes as well as traveling cards, identity cards and etc. Each year the number of confiscated counterfeit notes is increased on 10%. 

The Specific Programmes are under preparation as well, in order for a rapid presentation after the adoption of the FWP, and it is hoped that the first calls for proposals can be launched by the end of the year. 

After many decades of application, industry has completely accepted standard NDT as an inevitable but invaluable part of production and maintenance of components. Its application has been well-regulated, acceptance criteria for weld defects exist, good schemes for personnel qualification are in place and equipment has evolved to a standard of nearperfection. NDT has become a commodity. Pioneering years are over. 

NDT has a very important formal status. Requirements for performanee of NDT, acceptance criteria and requirements for personnel qualification are implemented in codes and standards. The NDT procedure is part of the contract. During the many years that NDT methods have been used in industry a well-established situation has evolved, enabling the use of NDT for the evaluation of welds against Good Workmanship Criteria on a routine basis, thus maintaining workmanship standards and minimising the risks of component failure. 

Although the present Good Workmanship approach actually gives conventional NDT methods the credit they deserve (their capabilities are well-used), there should nevertheless be a certainty beyond reasonable doubt that an accepted weld is fit for service. Many years of industrial experience have demonstrated that this certainty statistically exists. We are not doing things totally wrong. 

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