Well plans created using static geological interpretation and modeling tools rarely match the real world geology encountered during drilling. Conventional well planning solutions spread the Interpreting While Drilling (IWD) workflows across multiple applications and data management modules, making it difficult and time consuming for asset teams to integrate new data in order to reconstruct the geological interpretation. Increasingly more complex drilling environments call for more accurate predictive well planning, using real time operational decisions to drill more cost-effective wells.

In this Recon newsletter we will describe a project in which Recon was used to change the geological interpretation while a horizontal well was being drilled in an offshore exploration environment. Using Recon to monitor the LWD results enabled the asset team to closely cooperate with the drillers in adjusting the well plan in real time.

The advantage of Recon’s Interpretation While Drilling (IWD) workflows is that they are integrated with Recon’s 3-D geological interpretation environment, combining 3-D views with cross-section and basemap views to give the asset team the most comprehensive view of the subsurface situation and enabling the team to change its interpretations on the fly.

There are several ways to integrate logging while drilling (LWD) data and measurement while drilling (MWD) into Recon during the drilling process. In this example, Recon accessed the Landmark OpenWorks® database to access WITSML (Wellsite Information Transfer Standard Markup Language) data for real time monitoring of the well trajectory and LWD data. WITSML was developed by an industry consortium that includes BP, Statoil, Shell, Halliburton, Landmark, Baker Hughes and Schlumberger. Using Recon’s 3-D interpretation environment, the asset team made real time interpretation adjustments of the subsurface data and actively adjusted the drilling plan in order to ensure the success of the exploration well.

The problem with conventional geological modeling and interpretation software occurs when the asset team compares the predicted subsurface earth model with the actual measurements during drilling. When a deviation between the predicted data and the subsurface reality occurs, there is a need for an adjustment to the geological interpretation, which in turn leads to the possible necessity for an immediate drilling plan adjustment. Recon’s real time interpretation environment, powered by Recon’s Cascade Technology™ is the ideal tool for this challenge.

In this example, Recon was brought in to monitor the drilling of several horizontal wells in an offshore exploration environment involving unconsolidated sandstones. In previously drilled wells in the field, the asset team had executed the drilling plans without having had access to tools enabling them to analyze their data in order to recommend adjusting the well trajectory based on LWD information.

Using Recon for the new wells, the well trajectory and real time logging data was loaded into Recon as soon as it became available, and was visualized in 3-D in combination with depth-converted seismic structure horizons. One of the challenges faced by the asset team was the need to design a planned well path that stayed within a thin payzone, bounded by non-hydrocarbon bearing zones.

Using a chronostratigraphic framework to slice 3-D seismic reveals important geomorphological information. Recon StratalSlice™ is a Recon module which enables you to easily combine seismic structural and stratigraphic horizons with 3-D seismic to create a stratigraphically layered 3-D seismic volume that reveals depositional patterns.

Once the StratalSlice volume has been created, you can access it in Recon's basemap. When you slice through the StratalSlice volume in the basemap, a 3-D StratalSlice indicator horizon will automatically appear in Recon's 3-D window, displaying the geomorphological patterns in their proper 3-D spatial setting. The example shown in the figure above demonstrates the usefulness of analyzing geomorphological patterns in a 3-D stratigraphic view.

The example in the figure above was taken from a West Texas carbonate field, with a shelf margin depositional environment, showing grainstone distributions and debris flows along the edge of the slope. Note how much easier it is to identify the turbidite flows when analyzing the StrataSlice in 3-D as opposed to viewing the slice in the basemap.

Stratal slicing is just as powerful in fluvial depositional settings, as is shown in the above figure. Here we compare conventional time slicing through a 3-D seismic volume with the results of a Recon StratalSlice volume. Notice the clear definition of meandering channels in the StratalSlices shown on the right.

AGM specializes in developing next-generation 3-D geological interpretation software deployable on a wide range of computing hardware, from low-cost desktop workstations to large-scale immersive visualization centers. Visit the company's website at www.austingeo.com.