KAPPA ECRIN TOPAZE v5.4

Rate Transient Analysis, or RTA, is the natural complement to Pressure Transient Analysis (PTA) when one has pressure and rate data. RTA can be used to increase the area of investigation when compared to using PTA alone. Advancements in RTA have progressed partly due to the development of permanent downhole pressure gauges. Users are able to obtain answers that were previously only available from PTA. The advantage is that information is available at no extra cost as there is no deferred production. RTA started in the 1920s on a purely empirical basis, and as a financial tool however it has now evolved to a modern methodology that shares a lot of analysis and modeling tools with PTA. The long-term production can be modeled and forecasting is based on real models as opposed to an empirical function.

Topaze is fully compatible with Saphir data and models. An extensive analytical model catalog and numerical capability provides reliable history matching and forecasting.

Data loading in KAPPA-Workstation

Topaze can load an unlimited number of gauges, rates, pressure and other data in almost any format including ASCII, Excel.

Data transfer from KW modules

Data and/or models can be transferred from other KW modules by a simple drag and drop using the KW Browser. Data can also be brought in from KAPPA-Server, which offers several filtering options, and updated by the press of a single button, as new data becomes available in the historians.

Blasingame plot

Blasingame plot may be used for variable flowing pressure conditions. This plot is available in Topaze and is used as a diagnostic tool, where the data and a model response are compared. The model can be any model, analytical or numerical, single or multi-well.

Analytical models

Topaze offers a comprehensive built-in analytical catalog combining well, reservoir and boundary models, complemented by external models.

Additional capabilities include rate dependent skin, changing wellbore storage, interference from other wells, gas material balance correction, well model changing in time, horizontal and vertical anisotropy.

Improve tool

This option is used to improve the fit between the actual data and the current theoretical model by varying the selected parameters of the model.

It is possible to regress on both the log-log and the history plots.

Arps plot

Decline curve methods were formalized by Arps in 1945 and have been for many years the conventional technique for analysis and forecasting production data. Topaze includes this classical technique when pressure data is not available.

Once the decline parameters have been obtained, the recovery at abandonment can be calculated based upon an abandonment rate or time.

Decline curves have limitations based upon the assumptions that the bottom-hole pressure, well behavior and drainage area are all constant. Modeling the behavior with pressure data and by using a model based approach, avoids these limitations.