Knowledge Base

Landing String Stresses

by Paul Nardone

There is a lesser awareness of the combined stresses that occur in the upper work string which are not addressed in the standard tubing stress analysis study. Most well test and completion engineers are at least aware of, if not very familiar with, tubing stress analysis, a study performed during the early design phase of the well test to assess the effects of the various load conditions on packers and tubulars in the well-bore. Multiple varied load cases are considered during this study, typically starting with the as-installed state, then evaluating production, well kill and credible contingency scenarios.

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Well Testing Measurement or Experiment

by Nick Last

A well test is often viewed as a measurement process which attempts to specify well performance, determine reservoir deliverability and architecture, and gather fluid samples. Although it's useful as a shorthand description, the use of the term “measurement” is misleading. When we report the results of a well test - for example, “the reservoir has a permeability of 525 mD and the well has a skin of +6.5” - these results must be understood as interpretations and not as measurements.

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Estimating Zonal Gas-in-Place in a Commingled Well Using Results from Production Logs

by SPE paper 158733 published October 2012

It is becoming increasingly common to commingle two or more separate gas reservoirs in a single wellbore, especially in stacked-sand environments such as those frequently found in the Asia-Pacific region. Providing certain conditions are met, the total gas initially in place (GIIP) of the commingled reservoirs can be estimated using conventional material balance techniques. However, allocation of total GIIP to individual reservoirs presents a significant challenge. SPE paper 158733 describes how production logging (PL) results can be used, in conjunction with suitable dynamic modeling techniques, to define GIIP on a zone-by-zone basis.

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Safety Slick Joint

by Paul Nardone

This tool is intended to prevent catastrophic failure of the landing string in tension following a compensator lock up event. It allows the workstring to strip through the pipe rams and so prevent an over tension of the landing string leading to catastrophic failure.

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Hydrates & Well Testing

by Paul Nardone

Hydrates are ice-like solids that form when hydrocarbons and water mix under certain conditions of temperature and pressure. These solids can form at temperatures well above the freezing point of water and often present a hazard during well test operations.

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