3D static modeling in Petrel PDF

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3D static modeling in Petrel Dr. Arzu Javadova The main goal of modern development of hydrocarbon deposits aims at the most complete extraction of their recoverable reserves under maximum economic profitability. Advanced technologies are used to achieve the most and enhance oil recovery ratio. One o...

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3D static modeling in Petrel Dr. Arzu Javadova

The main goal of modern development of hydrocarbon deposits aims at the most complete extraction of their recoverable reserves under maximum economic profitability. Advanced technologies are used to achieve the most and enhance oil recovery ratio. One of the key technologies is computer modeling. • Field development history match and its forecast allow optimal development of hydrocarbon deposits with the least costs. • The main problem, when drawing up project documents is due to discrepancies between the static (geological) and hydrodynamic models • 3D modeling solves the following tasks: • • • •

calculation of hydrocarbon reserves, planning (design) of wells, assessment of uncertainties and risks, preparation of the basis for hydrodynamic modeling.

• The construction of three-dimensional geological models in the present time has already become a main component of technological processes for justification of well drillings and drawing of development plans for hydrocarbon deposits, including efficiency of proposed geological and technological measures. This is largely due to the increasing complexity of the fields and new production technologies, for example, drilling of horizontal wells.

The emergence of three-dimensional geological modeling as an independent branch was possible due to the following main factors: • development of mathematical principles and algorithms of three-dimensional modeling, • development of adjacent areas of geological and geophysical knowledge - processing and interpretation of 3D seismic prospecting, sequence stratigraphy, and also three-dimensional hydrodynamic modeling, • the emergence of sufficiently powerful computers and workstations, allowing to perform complex mathematical calculations with sufficient speed and visualization of results, • development of commercial programs providing a cycle construction of threedimensional models (loading, correlation, mapping, building cubes , visualization, data analysis, issuing graphics, etc.) • accumulation of extensive experience in two-dimensional geological modeling, reserves estimation and oil and gas field geology.

Schlumberger company distributes the Petrel package for 3D modelling which develops continuously and actively. What is Petrel? • A Windows PC software application intended to aggregate oil reservoir data from multiple sources. • I su ar , it addresses the eed for a si gle appli atio to support the “eis i -to- “i ulatio workflow reducing the need or a multitude of highly specialized tools. • It is used: To interpret seismic data; Perform well correlation; Build reservoir models; Calculate volumes; Produce maps; Etc. simulate

• A Geologi al

odel is a o puterized represe tatio of portio s of the Earth s rust realit .

• Hardware and Application Needed: A PC with a minimum of: For Petrel 64-bit:4GB of RAM; however; 16GB of RAM is recommended for optimum performance.( 6GB ); For Petrel 64-bit: Microsoft Windows latest updates , Vista 64 or XP 64 • A graphic card compatible with Petrel and a Petrel license and license key • Petrel Seismic to Simulation Software with the latest updates • Training datasets •

Required source of data and main software products for geological modelling is: • Coordinates of wellheads, altitudes, inclinometer which are used to create well trajectories in the model. It is important to note, that recently in all old wells repeated inclinometer measurements were compulsory to be collected and taken into account. The trajectory is recommended from the position log (X, Y, Z), using the well head coordinates calculated by the mine surveyor service in three axes. The correction tables for inclinometer are used to introduce corrections in altitudes of wells (for "shifts" of wells), assuming inaccuracies in the analysis of structural surfaces and fluid contacts. • The coordinates of the stratigraphic intersections are used to control the cross-sections, calculated in a project after the correlation of strata, as well as to create artificial vertical wells in the model when there is no inclinometer data. In this case, the coordinates of the well head are taken equal to the coordinates crossovers, and the altitude is the sum of altitudes and elongations on the roof formation. Comparing the coordinates of the intersection provides algorithms for calculating well trajectories from information on angles and azimuths which may vary in different programs. • Stratigraphic tops (markers) calculated by the geologist in project - are used as a basis for the formation of structural skeleton

• GIS curves are used for construction of correlation, lithotypes, saturation and reservoir flow performance, facies analysis, binding of seismic data. Results of GIS interpretation are used to construct a 3D model for distribution properties - the construction of cubes of reservoir flow performance. • Top of fluid contacts in wells is used for building maps of fluid contacts and reservoir geometrization. Interval perforations, test and work results of wells, hydrodynamic logs are used to justify and correct the position of fluid contacts. • The dates of drilling and putting wells into production (under injection), maps of accumulated sampling and injection are used in the selection of wells with initial saturation values. • Seismic data. Structural maps and fault surface from seismic, drilling and other methods are used to form a structural framework. Maps or cubes of seismic attributes are used for the spread of reservoir flow performance in the inter-wellbore space. • The equations of petrophysical dependencies of the "core-core" and "core GIS", mean and boundary (min, max) values of reservoir properties, capillary pressure curves are obtained from the results of a joint interpretation of core and GIS data and used to calculate the reservoir flow performance with assumptions for lithotypes and to construct a transition zone model.

• Quantitative and qualitative (description) core research. Applied when configuring GIS data for subsequent mass interpretation, as well as when creating a conceptual model. • General and geological data: • maps of effective and oil-saturated thicknesses of 2D (from the calculation of reserves) - used to control the quality of construction and, if required, adjustments to the 3D model. Summary table of counting parameters and hydrocarbon reserves is used for quality control of construction and, if required, adjustments to the 3D model. • Topography, license areas, OWC, faults, substitution zones and pinching out, water protection zones, categories of reservoir - are used as input data for a twodimensional map construction and 3D modeling, to control the quality of construction and, if necessary, adjustments to the 3D model. • the text of the report on the calculation of reserves (project document), reports on the study of subsoil are the actual basis for the reservoir estimation and modeling.

As a rule, data collected from various sources is loaded into the Petrel modeling software and a new working project is drafted. Petrel, as a most modern geological modeling package, has an organizational structure file

A typical set of main modules of the Petrel package for dimensional geological modeling includes

• I port a d e port of data, • orrelatio of sea s ell data, • i terpretatio of seis i data as a rule, this is a sele tio iolatio s, tra i g of horizo s a d mapping, attribute- analysis, that is, "seismic for geologists"), • data a al sis o stru tio of G“‘s, ross-rafts, variograms, histogram), • uildi g a d editi g aps, poi ts, pol go s, • o stru tio of a odel of te to i distur a es, • o stru tio of a stru tural-stratigraphic framework, • a eragi g the ell data to a grid, • lithofacies modeling, • petroph si al odeli g, • esti atio of reser es, • ell pla i g, • a al sis of u ertai ties a d risks, • al ulator u es, aps, logs, attri utes , • dra i g up of report graphi s.

If necessary, this kit includes a simulation module of fracturing as well. As a rule this set does not include the interpretation module of logging curves. Petrophysics usually perform interpretation of logs within a separate specialized package.

Traditionally, the technology of geological modeling is represented as the following main stages: 1. Collection, analysis and preparation of necessary information, data loading. 2. Structural modeling. 3. Creation of a grid (3D grid), averaging (transfer) of wells data to the grid. 4. Facial (lithological) modeling. 5. Petrophysical modeling. 6. Calculation of hydrocarbon reserves

• After loading the original data in the working project the structural-stratigraphic framework of the model is created. For this purposes the correlation of wells is pre-performed (inserts the stratigraphy tops of each layers of wells), reference seismic horizons are traced and a model of fault tectonics is created. • Next step is based on the given framework within the defined boundaries of the model and the selected horizontal size of the cells. The model is built as a frame which consists of horizons – the stratigraphic boundaries of strata tied in correlation stratigraphy tops and to the surfaces of fault tectonics. • Further, taking i to a ou t the patter s of sedi e tatio for ea h la er, a thi sli e" of the layers is performed. This is a way of creating a three-dimensional grid (3D grid). The grid cells along the trajectories wells carry out averaging of GIS interpretation results- facies curves, lithology, porosity, oil saturation, etc. Sometimes this procedure is called rescaling. • Based on these well data, using the seismic interpretation results as a trend parameters (if any), next step is to calculate property cubes in the grid cells and in the inter well space. • First step is to build a discrete cube of facies (lithology). Then, taking into account the distribution form and spatial regularities for each facies, cubes of porosity Kp and permeability Kp are constructed. • The continuous cube of oil and gas saturation of Kng is calculated on the basis of data on rock properties (Kp, Kp), formation fluids and regularities of capillary-gravitational equilibrium (models of the transition zone). For some types of rocks the transition zone may be absent. Preliminary fluid contact surfaces are built for each layer.

• Based on these cubes and rock flow performance, HC reserves and well design are calculated, then the model provides hydrodynamics for calculation of flow performance . With the advent of a new information (drilling wells, shooting new 3D seismic cubes, implementation of additional core research, etc.) the model is supplemented and corrected. • Another reason for adjusting the geological model is remarks from reservoir engineers (hydrodynamics), justified by the results of adjustment of the flow performance model in the course of the field development history. • Now we consider the most common deviations and additions for the traditional order of geological modeling. Ignoring the facies modeling phase, a simplified approach to modeling can be used in the case, when a discrete cube of facies is not constructed, but continuous net-to-gross cube (NTG) or porosity is used to characterize cell quality. Second, an additional stage of a multivariate modeling step flows up with estimation of uncertainties in the geological model and risks of well location. As a rule, this stage is practically a standard approach of most western oil companies. Depending on the task, it is possible to exclude any stage or to repeat it. Using Petrel manual we briefly dwelled on a traditional order in detail, which is covered in the following slides

Petrel static modelling PETREL MANUAL FOR FIELD DEVELOPMENT PROJECT 1. MAKE SURFACE FROM BITMAP/IMAGE 2. MAKE SIMPLE GRID 3. IMPORT EXPLORATION WELLS 4. IMPORT WELL LOGS 5. IMPORT WELL TOPS 6. MAKE ZONES: CREATE ISOCHORES 7. MAKE ZONES 8. MAKE LAYERING

9. PROPERTY MODELING 9.1 SCALE-UP WELL LOGS 9.2 PETROPHYSICAL MODELING 9.2.1 Deterministic modeling 9.2.2 Stochastic modeling 9.3 SCALE UP PROPERTIES 9.3.1 Scale up Properties process 9.4 GEOMETRICAL MODELING 9.4.1 Create a bulk volume property. 9.4.2 Create a cell angle property 9.4.3 SW calculations: Create Above Contact Property 9.4.4 Property Calculator

10. MAKE CONTACTS 10.1 MAKE CONTACTS – GOC AND OWC 10.2 VISUALIZE CONTACTS AS PROPERTIES IN 3D 11. VOLUME CALCULATION (PRACTICE MANUAL) 12. UNCERTAINTY AND OPTIMIZATION 13. MAKE FLUID MODEL 13.1 IMPORT FLUID MODEL INTO PETREL 14. MAKE ROCK PHYSICS FUNCTIONS 14.1 MAKE A SATURATION FUNCTION 14.2 MAKE A ROCK COMPACTION FUNCTION 15. INITIALIZATION 15.1 MAKE SATNUM REGIONS FOR PERMEABILITY

1. Make surface from Bitmap/image 1 - Import bitmap file 1. Right click on the Input pane > Import (on tree..)

2. Browse the image file

3. Change File of type to Bitmap image 4. The image item appear in Input pane

2 – Setting the bitmap image 1. Right click the image item on input pane > Setting 2. In the Setting window > Setting tab 3. Select Continue spatially unaware when prompted

3 – Set the coordinate 1. Choose on Located in world 2. Select the origin 3. Select Independent edges 4. Give a coordinate for x, y and z

4 – View image in 3D window

5 – Make surface 1. From the utilities pane, select Make/ edit surface 2. Make surface window, drop bitmap image to main input 3. Name the surface 4. Geometry tab – click on Get limits from selected 5. Select the grid increment

6 – Select method 1. Algorithm tab > select Method 2. For simplicity, select Surface res ampling 3. Click Apply & OK 4. You can see the surface created in the Input pane

7 – Adjust colour scale 1. Created surface can be viewed on 3D window 2. Click on Adjust colour icon to bette r view the surface

8 - Exaggerate surface in Z-direction • This process is to specify the surface ele vation depth as given in data provided. 1. Right click the surface in Input pane > Setting 2. Operation tab > Arithmetic operations > Z=Z*Constant 3. Give a constant value 4. Run 5. Click OK for changing the contour line spacing

9 – View created surface 1. Surface can be viewed using 3D window 2. Repeat step 7 to adjust the colour scale

10 – Smoothen the surface 1. Right click the surface in Input pane > Setting 2. Operation tab > Surface operations > Smooth 3. Run 4. Further adjustment can be done by changing Iterations and Filter width input value

11 – Before and after

Top – Before

Bottom - After

12 – Adjust Z elevation for surface

“urfa e s Z elevation can be adjusted 1. On the Operations tab > Arithmetic operations > Z=Z+ constant 2. Give the new elevation. – ve value indicate below from the reference position 3. You may check the output operations in Statistics tab.

Make more surfaces 1. This method can be repeated to create severa l surfaces. 2. Make another 3 surfaces of Base Cretaceous, Top Tarbert and Top Etive. 3. These surfaces are different from the previou s Seabed. They will be used to make a simple grid. Base Cretaceous 1. Import the bitmap file of Base Cretaceous 2. Follow the same procedure of the previous st eps on how to create a surface.

3. Insert the coordinates. 4. When you view the image of the Base Cretaceous in a 3D Window, you will see the surface of Base Cretaceous is bounded by outer white s urface area. This white surface area is captured along together from the bit map, thus we need to eliminate it out.

5. To accomplish this, a polygon needs to be made first. 6. Follow the next steps to make a polygon.

Make polygon 1. Open a 2D Window and view the image. 2. Expand the Utilities under the Processes pane and cli ck on Make/edit polygons once.

3. Click Add new points

at the toolbar.

4. Make the polygon around the surface. Once you don e until the end, click Close selected polygon(s)

to close the polygon.

Make surface – Base Cretaceous

1. Open the Make/edit surface in Utilities pane. 2. Drop the surface into Input data. 3. Drop the Polygons from the Input pane into the Boundary. 4. Name the surface to Base Cretaceous. 5. Click Get limits from selected. 6. Select the grid increment of 40 in both X and Y. 7. In Algorithm tab, select Surface resampling 8. Click Apply and OK.

9. View the Base Cretaceous surface in a 3D Window. The outer part surface area has now already been eliminated.

10. Adjust the colour scale.

Exaggerate Z direction 1. Open the settings of Base Cretaceous and view the Statistics tab 2. The elevation depth of the surface is as stated above. The real delta of the surface is to be 333. 3. Open Operation tab > Arithmetic operations > Z=Z*Constant 4. Enter the Constant value to match the real delta. 5. Click Run.

Smoothen the surface 1. Smoothen the surface. Operation tab > Surface operations > Smoot h. 2. Specify the number of iteration to use. 3. Click Run and view the surface changes.

Adjust Z elevation 1. View the Statistics again. 2. Compare the current minimum elevation and the correct minimum elevation of Base Cretaceous. 3. On the Operations tab > Arithmetic operations > Z=Z+Constant

4. Give the new elevation. –ve value indicate below from the reference position. 5. Check the statistics again and check to make sure the Base Cretaceous is at the correct elevation. 6. Make the surfaces for Top Tarbert, Top Ness and Top Etive using the same previous steps.

2. Make simple grid 1. Open the Make simple grid process located under Utilities in the Processes pane. 2. Select a name for the new grid, for example 3D Grid. 3. On the input data tab, select the Insert surface option. 4. Drop in the surfaces Base Cretaceous, Top Tarbert, Top Nes s and Top Etive from the Surfaces folder on the Input pane by clicking the Append it em in the table button

.

5. Select the Geometry tab, and click the Get limits from selected button.

6. Select a Grid increment of 40 m in both the X and Y direction. Click OK.

7. Your grid is now stored in the Models pane. Select to view the s keleton grid in a 3D window.

3. Import Exploration Wells 1. Create a well folder. (Insert > New well folder) 2. A new wells folder is created at the Input pane. Right click on the wells folder and select Import (on selection..) 3. Open the Well Dev folder (Wells>Well Dev). Change the files of type to Well path/deviation (ASCII) (*.*)

4. Select A10 file. The File must be in type of DEV file. Click Open.

5. A match filename and well will pop out. In well trace, select Create new well. Click OK. 6. In the Import multiple well paths dialog box that opens, select X, Y, TVD as Column input data. 7. Look at the file capture at the bottom of the import dialog and type in the correct column number for X, Y, and TVD. Click OK.

4. Import Well Logs 1. Again, Right click on the wells folder and select Import (on selection..) 2. Open the Well Logs folder (Wells>Well Logs). Change the files of type to Well logs (LAS) (*.las) 3. Select A10 file. The type of file must be a LAS File. Click OPEN. 4. In Match files and wells, match wells by using Well name and well name based on LAS header.

5. Click OK. 6. In Import well logs, select Automatic matching and click OK. 7. Expand the A10 well in Input pane, and expand the well logs. Try to display the imported logs.

Import Other Wells Import more exploration wells by repeating the same steps previously. All the exploration wells are with name of: •

A10

•

A15

•

A16

•

B8

•

B9

•

C2

•

C3

•

C4

•

C5<...