Introduction To Well Testing

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SYEDA MISHA QAZI 2011-PET-64

INTRODUCTION TO WELL TESTING

•1

Introduction To Well Testing

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Types Of Well Testing

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Well Test Interpretation Methodologies

• 4

Introduction To Ecrin Software & Conclusion

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Introduction To Well Testing

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“Well testing is the technique and method for the evaluation of well conditions and reservoir characteristics”

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Initial reservoir pressure Average pressure Permeability Skin(formation damage and stimulation) Communication between wells Flow barriers and fluid contacts

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A step by step process is required to find the well test interpretation model • Identification of interpretation model

• Calculation of the interpretation model parameters • Verification of interpretation model

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ETR (Early time region): During which pressure transient is moving through the formation near the well bore. •MTR (Middle time region): During which the pressure transient has moved away from the well bore . •LTR (Late Time region): During which radius of investigation reached the boundary 9/12/2014

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Types of Well Testing

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Well testing is divided into two major categories which are further subdivided into different types: • Pressure Transient Testing  Build up test  Draw down test • Deliverability Testing  Flow after flow test  Isochronal test  Modified isochronal test

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The well is first produced at a constant rate till pressure is stabilized and

Then the well is shut in.

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Shut in the well till pressure stabilizes Then flow the well at a constant rate q & measuring Pwf.

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Well flows under a constant rate until it reaches stabilized conditions (pseudo steady state). After the stabilized rate and pressure are recorded, the rate is changed and the well flows until pressure stabilizes again.

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An isochronal test is conducted by flowing a well at a fixed rate, then shutting it in until the pressure builds up to an unchanging (or almost unchanging) value.

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In the modified isochronal test shut-in periods are of the same duration as the flow periods

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Well Test Interpretation Methodologies

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“A conventional technique for reservoir parameter determination is semi log analysis. In this analysis technique the pressure data is plotted versus time”

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The pressure derivative curves have given the well testing a new dimension in resolving the issues related to reservoir model identification

• Ramey’s type curve • McKinley type curve • Gringarten type curve • Bourdet type curves are one of the famous derivative type Curves.

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Introduction To ECRIN Software

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Ecrin is the most powerful tool for well test analysis in the industries. It has different modules that can help to identify model and predict the reservoir behavior.

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Aid the interpreter to choose the model that may finally match the data and yield the results The diagnostic phase includes the search for all flow regimes that may be present in the response of the extracted period. This will allow you to run a non linear regression to improve the match between the model and data.

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• Well testing is one of the most important tools for understanding and characterizing our reservoirs. • Well testing is based on analyzing draw down or buildup data. • This analysis involves study of pressure on semi log plot and derivative plot. • Ecrin is the commercial software to understand and interpret the reservoir parameters.

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 Pressure Transient Testing by John Lee  Reservoir engineering handbook by Tarek Ahmed  SPE 102079-”From Straight Line To Deconvolution: the Evolution Of The State Of Art In Well Test Analysis” by A.C.Gringarten (2006)  Well Testing And Interpretation by D.Bourdet  Saphire guided session #01 by Kappa (1988-2008)

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