Hydrocarbon Data Systems
User Q & A

Question: Will HDS currently install and execute properly under the Windows Vista operating system?


Answer: Yes our software installs and runs seamlessly in Vista 32 and Vista 64.


Question: If I do a multiple linear regression and get a good fit between Dt and Dens, how can I use it in tweak processing?


Answer: The Multiple Linear Regression option will generate equations. To create a curve from the MLR equation, it must be used in 1 of the 2 user equation methods. Select “Custom User Equations” under the main menu option, “Calculation”. This is a tweak style of processing (graphical). You will setup input and output curves, then click the code icon and paste the equation into the marked code area. Once the curve is processed, it can be used in other options of the HDS program. The other way to use it in tweak processing is to select the User Equation option from the “Standard Calculation” menu. In this option, the first line of code must read 'output (curve name)’, so whatever you plan to call the curve must be identified as something like ‘output PhiD’. In either case, the equation can be pasted into the code and a curve will be generated. If it is a curve that can be used in tweak processing, then the new curve can be selected from the “Input Curves” options in tweak processing.


Question: I want to do a simple display on the log plot that shows >3% porosity to be pay and <1% porosity to be tight rock. Is there a simple way to create a curve or something that I could put in the log track?


Answer: The shading for phi >3% and <1% goes as follows. The example curve is PhiE and the example scale is left-20 & right-0. Go to the Curve Setup menu with PhiE being the selected curve and fill to the right with a value of 3% and to the left with a value of 1%. The colors for each curve can be defined by you.


Question: On the log footer there is a “Sw” and a “Swa”. I am running a modified Simandoux and so I thought the Swa might be an Archies calc., especially since the values are somewhat higher. When I go back and switch to the Archies, these two values are the same but they are not the same as the previous Swa. Can you explain what Swa is?


Answer: If Sw is being used as a cutoff value then in Case 1 it is using the Simandoux and in Case 2 it is using Archie. Since the log footer displays the pay totals summary only the net feet in case 2 is most likely less than the net feet in case 1. So you have removed the higher Swa (archie) depths from the summary and the results should be, case2 Sw and Swa summaries will with different and lower #'s. 


Question: In New Style Cross Plots, the displayed log plot and companion plots to the right of the cross plots are very linear, like if the sampling rate for drawing the log plot is one sample for 5 feet or one sample per 10 feet.  The GR curve, for example, only very generally resembles the continuous curve.  How can I set this to show the continuous GR log plot and companion plots?


Answer: Plotting thousands of feet of data at smaller sample rates on a small area does not allow for all of the depths to be plotted. To get more definition, zoom in by clicking on 2 separate points on the depth track. It will zoom to the selected depth range more of the data will be plotted. To get it exactly as you would on a 5" scale, the zoom will need to be over a small area. To un-zoom, click on the (yellow) depth header. 


Question: Where can I find the pay summaries spreadsheet that I can edit or make changes to?


Answer: The pay summaries spreadsheet is found by going to the HDS main screen, selecting “Printouts” from the menu bar and choosing the option “Run Printouts”. After doing so you will have two options: Payzone Averages (filtered cutoffs) and All Data (no filters).


***If you have more questions/answers that may help the HDS community, please email them to PatrickMcKee@hds-log.com***