APSG_US_West. January 20, Stigant Enterprises -

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1 APSG_US_West January 20,

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3 This shows the difference between rectified and unrectified imagery. On this example the extreme areas of the image are moving by up to 1 mile!!! 3

4 The breakwater of Plymouth Sound in England per Google Earth. Be careful of free gifts! Also note that Google can use your search to make an educated guess about what organization you belong to and what your geographical interests are information which, if in the hands of a competitor or opportunist could be very damaging to your interests. 4

5 APSG_US_West January 20, 2012 Wrong Boundaries affect where a well appears on a map. It also affects well placement planning, number of wells that can be drilled, potential interference between wells, possibility of collisions, royalties, lawsuits.. Stigant Enterprises Inc - jonsce@att.net 5

6 This slide shows a summary of well location reviews conducted over the last few years. The average error between actual location and various other sources is documented at 26%. A total of well locations have been reviewed. The various sources are: Vendors of industry data Application links to online databases Company Projects Company Databases It is noteworthy that there are some distinct outliers at both ends of the spectrum. Some projects and areas showed significant errors at the 50% level others at 5%. User and application developer education is one key to reducing errors in databases 6

7 APSG_US_West January 20, 2012 Amazing percentage of discrepancies between sources! Stigant Enterprises Inc - jonsce@att.net 7

8 The diagram shows a 3D survey in pink and a proposed well location. The dotted red lines show the anticipated calls from the section lines. Unfortunately the mapped section lines are misplaced and are actually where the black solid lines are. This will lead to a misplacement of the well relative to the seismic data equivalent to the offset of the section corner as shown by the green line. To avoid this, have the land man provide a latitude and longitude with a GPS receiver and then send it in. Of course you will need to datum shift this to the project datum in order to make and apples to apples comparison. If it doesn t agree when you have done this, then don t drill the well until you have someone check it out 8

9 The above diagram shows the result of re-surveying all the straight (un-deviated) wells on a prospect! The price of this is huge if you switch the numbers it represents a 300% improvement in efficiency of geoscience personnel! 9

10 Test dataset provided by SPE to check wellbore software integrity 10

11 One application can switch the surface and bottom hole locations. If you were conducting the SPE test you would probably see it. If you are loading 1,000 wells, you probably wouldn t! 11

12 1. The Blue grid shows the first projection you are using. 2. The red shows the projection you want to change to. 3. The origin is the well reference (KB or Drill Floor or Ground Level). 4. The blue lines show the deasting and dnorthing for the black dots which define the well trajectory. 5. Grid north is different, since the location of the well in one projection is different relative to the central meridian than the other. 6. Central Meridian definition: a. A central meridian is a longitude that passes through the center of a projection. b. The central meridian is often a straight line that is an axis of symmetry of the projection. Stigant Enterprises Inc: jonsce@att.net 12

13 Here is what happens if you use the blue deasting and dnothing on the red projection. 1. It rotates the well trajectory in space. 2. Remember that the well trajectory doesn t move, we are changing the north reference, when we change the projection. 3. As you can see the potential damage to the integrity of the well trajectory position could be severe (increase with offset from the well reference point. Stigant Enterprises Inc: jonsce@att.net 13

14 APSG_US_West January 20, 2012 Data are constantly in a state of movement as an interpreter or reservoir specialist juggle in and out of the applications needed to evaluate all aspects of the data in the search for the best targets, drilling concerns velocity, pressure, porosity etc Interpretation Process 20 to 30 datasets per 3D survey, multiple well surveys, boundary, culture, raster, relief data. Calibrating Seismic and Well Data through matching traces to well logs (more difficult with directional and horizontal wells. Combining many heterogeneous datasets in major applications Using a set of 7-10 different Geoscience specialized applications some examples include: Finder (Schlumberger Well and Seismic database) OpenSpirit (Middleware) ArcGIS (ESRI GIS Mapping package) Petra (Geological, Engineering and Petrophysical Analysis with Seismic Interpretation and display tools) Hampson Russell, Jason, Prima Analysis and Processing (Reservoir Qualification and Quantification) Rock Solid Images Analysis and Modeling (Lithology, Porosity and Saturation) GXII modeling (Seismic Ray Tracing) RokDoc (Rock Physics Enabled Interpretation) Fusion SpecMan (Processing and Analysis of the Spectral Decomposition of Seismic Wavelet) Some of these applications are geospatially unaware and are not an easy environment to invoke geospatial integrity without potentially delaying of the operational momentum To emphasize the ubiquitous impact of spatial data. Entropy works it does not come out right unless the data are treated properly according to the criteria and principles espoused in this class. 14

15 Improper application of angular corrections (magnetic declination and convergence) can apparently rotate wells coming from different directions and create a false or ghost fault, giving a misleading idea of the subsurface structures. 15

16 Well data misplaced about 1800 meters and used for inversion. While one well may not cause too much trouble, 45% of the wells in this field were misplaced. This will create major bias in the inversion and subsequent use of the data for follow on drilling decisions. 16

17 Decline Curves used after a well has produced for some time and there is a reasonably predictable decline. Can be deceptive as some decline curves are straight once in steady state, some flatten out and are curved. Assumption is that decline will continue at the same rate as when observation was made. Often used to determine PDP Reserves (Proved, Developed, Producing) Volumetrics uses size and shape and characteristics of reservoir - aerial extent, thickness, porosity, relative saturations of oil, gas and water. Basic geometry is used Provides OIP (Oil in Place) and GIP (Gas in Place). Must use separate calculations to determine recoverable reserves. Often used for estimates of reserves prior to drilling and development PNDP (Proved, Developed, Not Producing), PUD (Proved, Un-Developed), Probable and Possible reserves Material Balance- Simply put, the mass of anything in a container is equal to the mass originally in the container, less what's been taken out, plus what's been added in. Requires a lot of reliable data. All methods have degrees of uncertainty and drawbacks. Need to do two or all three and compare results, to check results. Note that in each of the latter two cases, size shape and volume are used to some degree, which are wholly dependent on the integrity of the spatial data used to make the maps. 17

18 APSG_US_West January 20, 2012 Using the TRRC digitized maps and well locations, the Atoka thickness values were re-contoured. Shown versus the Kipco contours. Same gridding and mapping parameters used. 18

19 APSG_US_West January 20, 2012 Using the MidTex well locations, the Atoka thickness values were re-contoured. Shown versus the Kipco contours. Same gridding and mapping parameters used. 19

20 This is a cartoon of an actual case. The green and yellow lines show boundaries improperly represented in the database at two epochs 1993 and This resulted in 4 wells being misrepresented in the database by about 500 ft. The geologist finally visited the field to resolve this by speaking with the field surveyor. The correction of the boundary, the well locations and the redrawing of the contours at prospect depth showed commercial prospectivity in the two spots shown by the orange wells, which are 2 of the biggest gas producing wells in the US. They would not have been drilled without this extraordinary effort which cost 3 months analysis, and could easily have been shelved by a less dedicated geologist. With the challenges ahead of us, we cannot afford the kind of delay or missed opportunity this would have represented, let alone the loss of profits and reserve replacement as well as wastage of staff time! 20

21 Poor boundary mapping does not just create opportunities for trespass, they can increase or decrease the size of a unit or mineral lease, which may mean loss of drainage, improper calculation of reserves. 21

22 If geologists are uncertain about boundaries, they may allow feet of extra space at unit edge to mitigate the risk of a regulatory infraction. In this case a reduction in size of the drainable area of 25 acres, and possibly one complete well from 5 to 4 22

23 This and the next slide show the impact of interference between fracture zones when the frac locations are misplaced due to errors in measured depth. 23

24 The light blue frac zones are now directly aligned with the next door well, instead of interleaved. This will cause greater interference between the areas fractured. 24

25 This and the next 3 slides show the impact of either interference or gaps in drainage due to mishandling or miscalculating the orientation corrections to magnetic declination and convergence angle. 25

26 Interference and possible collision. This is quite likely if only one well is drilled to achieve HBP status and then several weeks or months later, another rig and crew is brought in to drill infill wells. 26

27 Back to the standard 27

28 This shows possible lost production due to a similar angular correction mistake as before but showing the gap between the wells increasing and subsequent potential loss of drainage. 28

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31 A lot of perforation and fracturing placement is done homogeneously and at regular intervals in spite of differences in mineralogy, rock type, facies changes and G&G structures and faults. More frac zones is better if they are in highly productive zones, but this is more expensive and is not economically viable if much of the zone is non productive. Differences in a custom vs a homogenous approach can return as much as $3-4 MM per well! 31

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33 Even well managed companies have 15-20% duplicates in their databases 5% have different coordinates for the same well, at the surface and more at the bottom hole. How well managed is your well database? 33

34 1. The Map Projection Editor displays the details of the selected CRS. You could also create a new user defined CRS. 2. When using predefined geospatial parameters it is important to ensure that the parameters are correct refer to the EPSG database. a. Predefined geospatial parameters in the OW database have been known to be incorrect either as a result of typing errors during data entry, incorrect choice of parameters or incorrect source information. b. The Geodetic group should be contacted before setting up a project, to help set up proper CRS and check that parameters are correct. 3. There is a lack of adequate security for the predefined and user defined geospatial information. Users are able to edit and delete this information. 4. During software upgrades, this information can either be overwritten or vital new information may not be updated 34

35 Investigate the well file that has been exported from OW. The UWI for the exported file is one digit more than the UWI of the original file. 35

36 In the ASCII Loader, Select Edit Format. The screen shots show how one column could cause a multitude of errors and creation of twice as many wells. 36

37 Examination of the wells generated as a result of incorrect column management reveal that the Total depth and well status are incorrect. 37

38 1. Incorrect format file has resulted in errors in TD values upon export. 2. Correcting the.wlx and.wdl files correct the TD values. 38

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41 APSG_US_West January 20, 2012 Some of the ways that good geospatial management can improve the return on investment in an oil and gas exploration and production company. 41

42 1. Historically there has been little or no attempt to classify, or Rank, the geospatial quality of the well data we use 2. This slide shows a slight variation on an attempt to rank international well data, 3. A 6 tiered approach was adopted to give quantification of geospatial assurance 4. For example, a well drilled by Company, with onsite positioning QC would merit rank 1 5. At the other end of the scale, a vendor well quoted to only 2 or 3 decimals of a degree with no geodetic definition would be ranked 6 42

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44 Will you be up to the task! Stigant Enterprises Inc - jonsce@att.net 44

45 APSG_US_West January 20,