Pressure Transient Data Acquisition and Analysis of Pumping Wells State of the Art

Abstract

SPE Members Abstract In this work the advances in pressure transient data acquisition and analysis of pumping wells are presented. A brief summary is presented on methods used in the past 20 presented on methods used in the past 20 years for testing pumping wells. A comparison is made between pressure data acquired using bottom hole gauges and that based on indirect calculation of the bottom hole pressure by determining the liquid level in the annulus acoustically measuring the surface annulus pressure, and calculating the bottomhole pressure, and calculating the bottomhole transient pressure. The quality of the acquired data using the previously mentioned method is the main topic of discussion and its use and/or limitations for reservoir and well evaluation. Several field examples are used to illustrate the presented methods. As a main result it is concluded that pressure data acquisition using acoustic methods is the best alternative for pumping wells. The pressure data resolution and accuracy is pressure data resolution and accuracy is similar to a conventional amerada type of gauge. However the main advantage is that we can get the whole pressure transient profile (flowing/buildup) in real time if necessary. This definitely provides an enhanced data interpretation that can be used for reservoir evaluation specially for secondary recovery projects. projects Introduction Formation evaluation using pressure transient analysis is a well known technology applicable to both exploratory as well as production or active wells. Recent advances in the theoretical principles for the analysis of pressure transient principles for the analysis of pressure transient data and in the resolution of pressure gauges permits a resolutive reservoir description for permits a resolutive reservoir description for the drainage area of the well tested. A good summary of the advances in practical well test analysis has been recently presented by Ramey. Much of the advances have been obtained during the eighties: Use of the derivative as a diagnostic tool, regression analysis techniques for data evaluation are just a few. Nevertheless and in spite of the recent advances there are many cases where a given analysis is subject to uncertainties and spec. It seems that both the reservoir model used to match the data and the particular well production system are factors that sometimes limit the acquisition and analysis of data. A good example of this are pumping wells. It is worth to mention here that there are many secondary recovery projects where production comes from pumping wells. Pressure production comes from pumping wells. Pressure monitoring using conventional amerada gauges is not quite accepted due to uncertainties in the measured wellbore flowing pressure just before shut-in. In many cases because of the lack of data during the early time region of the buildup period. P. 19