Saphire RFT Manual

7/25/2019 Saphire RFT Manual

1/10

Ecrin v4.20 - Doc v4.20.01 - KAPPA 1988-2011 Saphir Guided Session #7 SapGS07- 1/10

Saphir Guided Session #7

A01 Introduction

This guided session is an introduction to the functionalities of the Formation Test (FT) analysis

option in Saphir 4.20.

Warning: This Saphir feature is temporary, restricted to v4.20. We will remove it from later

Saphir versions, when an Ecrin module dedicated to formation testers is released. The

temporary Saphir addendum is aimed at unlocking our users who wish to have simultaneous

match of source and observation pressures. The future FT module will handle all FT surveys for

a given well in a single document. It will integrate a tool database, tool specific features, a

dedicated numerical model, gradients, contacts, etc. We cannot achieve a proper FT module in

v4.20, hence the temporary Saphir feature. Naturally, FT files created by Saphir v4.20 will be

read by following versions of Saphir and by the FT module.

In this exercise, the testing tool presents the following geometry:

Fig. A01.1 Testing Tool Schematic

The tool has a single sink probe, and measures 4 pressure signals at the active probe (DSP1),

at an interference probe opposite to the active probe (DQP1), and at two distant interference

probes located 2.3 and 17 ft away from the active probe (BQP1, BQP2). Those pressure data

are completed by the direct measurement of the pumped volume during the test.


2/10


B01 Creating a New Document and Loading the Test Data

B01.1 New Document Creation

Create a new document in Saphir. Set the analysis type to Formation Test, change the pay

zone thickness to 50 ft.

Fig. B01.1 Create a new document

In the PVT parameters page, keep the default values for the PVT parameters (B=1 B/STB, =1

cp, ct=3E-6 psi-1). Click on Create to proceed with the document initialization.

The first time such an FT analysis is created, the screen below is displayed with the warning

given earlier in the Introduction.

Fig. B01.2 FT Analysis warning


3/10


B01.2 Loading the Data

Click on Load in the Interpretation page ( ), and open the SapGS07.lasfile:

Fig. B01.3 Loading SapGS07.las

Click on Next to select all columns to be loaded as indicated below - downhole volume incolumn B, and all pressures in columns C to F units and names are automatically set from

the LAS file header.

Fig. B01.4 Selecting the Data Format in SapGS07.las


4/10


Finally, click on Load to import all gauges in Saphir. Once the load is completed, you may visit

the QAQC page to visualize all loaded gauges one volume gauge and 4 pressure gauges:

Fig. B01.5 Display of the Test Gauges in the Saphir QAQC Page

B01.3 Computing the Rates

Before to proceed further, we need to compute a rate gauge from the measured pumped-out

volumes. This is achieved in the Compute Q option ( ) which calls the following dialog:

Fig. B01.6 Compute Q Dialog


5/10


This dialog offers a variety of options for the derivation of the rates from the volumesmeasurements (select Help in this dialog for details on the various options). In our case, the

rate history is correctly calculated with the default settings you may keep them and click onOK to finalize the rate history construction:

Fig. B01.7 After the Rates Computation

B01.4 Defining the Testing Tool

Click on the Tool Info button ( ) in the Interpretation page. This dialog defines the

geometrical location of all available tool pressure probes. Use the Addbutton to create the 4test probes: DSP1, DQP1, BQP1 and BQP2.

Fig. B01.8 Tool Infos Dialog

Assign the corresponding pressure gauges in the Pressures column, and rename the fourprobes. Keep DSP1 as Active (single probe), and change Rw (the inner probe radius) to 1 in.

Keep all other probe types to Observation, and enter the correct measured depth values (Z)in front of each probe - only the relative distance of each probe to the active one is relevant forthe model. Please note the geometrical definition for the DQP1 probe: z=0 ft and Theta=180.

Once this is done, click on OK - we may now proceed with data extraction.


6/10


B02 Modeling and Fitting the DataB02.1 Data Extraction

Click on Extract dP to get the following dialog:

Fig. B02.1 Extract delta-P Dialog

Click on the List button in front of the Select

gauge(s) menu to check that all availablegauges are about to be included in theextraction step:

Validate all default choices and proceed with data extraction. The 4 gauges are plotted in the

Loglog and Semilog plots, as well as in the History plot:

Fig. B02.2 After Pressure Extraction


7/10


B02.2 Model Generation

Edit the model dialog by clicking the Model button ( ) in the Interpretation page:

Fig. B02.3 Model Dialog

In this dialog, change Zwto 15 ft Zw is the distance from the active

probe to the interval bottom. Usethe pick option and pick twice on

the plot to indicate the sphericalflow limits to set an approximatevalue for the vertical anisotropykz/kr:


8/10


Click on Generate, and wait until all models at all gauges have been simulated:

Fig. B02.4 After Model Generation

It appears on the loglog plot that the BQP2 (furthest) gauge may not bring any valuable

information for the matching procedure the measured pressure drop seems to fall within theprobe resolution.

In order to temporarily discard it from theinterpretation, click on Extract dP again, and uncheck

this gauge in the gauges list:

Click on OK and accept to re-generate the model.


9/10


B02.3 Improve

In order to obtain a better match, click on Improve ( ) and in the following dialog makesure that Zwis not included in the improved parameters list:

Fig. B02.5 Improve Dialog

Uncheck the Skin and accept all other default choices and click on Run - this will launch a non-linear regression on k and kz/kr, and on the 3 extracted gauges DSP1, DQP1 and BQP1 at once.

A very good match should be obtained after a few iterations:

Fig. B02.6 Match Obtained After the Improve


10/10


Double-click on the status window to view the

results:

As shown opposite, the final match wasobtained with a permeability of 25 md, andkz/kr= 0.05. Note the slight changes in initialpressure for each gauge: from Pi = 5000 psiafor the active gauge to 4997 psia for BQP1.

As a last confirmation, include back BQP2 in the extraction (Extract dP dialog) and accept tore-generate the model to confirm that at least the BQP2 match is not inconsistent with theresult obtained so far:

Fig. B02.7 Final Match Obtained on All Pressure Gauges

Saphire RFT Manual

Documents

Transcript of Saphire RFT Manual