Petrel TIPS&TRICKS from SCM

Transcription

1 Petrel TIPS&TRICKS frm SCM Knwledge Wrth Sharing Planning a Petrel Prject Ding a Petrel prject is like digging a hle in yur backyard. Yu start knwing hw big the hle is t be, hw deep yu will g, and that yu have tw hurs left befre it gets dark. Having dug hles befre, yu knw there is plenty f time t dig this hle s yu get yur tl, a shvel, and start digging. Unfrtunately, things dn t g as planned. Had yu taken a few minutes t analyze the situatin befre digging yu wuld have realized: A large tree is grwing abut 5 feet frm the hle The hle is n a line between the gas pipe leading int the huse and the gas meter at the prperty line Others wh have dug hles in yur neighbrhd have always fund a 4 inch caliche layer abut tw feet dwn. It is clear that a little planning wuld have tld yu that yu must: 1. Repsitin yur hle t avid the gas line 2. Have a saw r ax t handle the rts 3. Have a pick r jack hammer t break up the caliche layer 4. Refine yur estimate t be fur hurs instead f the tw yu thught wuld wrk 5. Make adjustments because yu will nt finish befre dark This simple hld digging task had a few surprises and was underestimated by a factr f tw. Sner r later, if yu use Petrel yu will have t estimate hw lng yur prject is ging t take and be reasnably accurate in that estimatin. Like digging a hle, yu must knw what yu are ging t create, the bstacles yu will encunter, and the tls yu will use t d the wrk. As cnsultants the authrs perfrm this analysis n each prject. Unless yu have dne many tens f Petrel prjects yur gut feeling r quick estimate f what will be required is seldm crrect and usually underestimates the time required by a factr f tw r three. This Tips & Tricks article discusses the prcess f evaluating, planning, and estimating time fr a Petrel Prject. The Interview Yur first task is t learn abut the prject fr which a mdel is t be built. Yu must determine what they (thse requesting the mdel) have, what they want, and hw lng yu have t get it dne. This is an interview prcess that usually last ne r tw hurs. At the end f it yu must have enugh infrmatin t write the mdeling prpsal. Questins t ask and infrmatin t be learned include: General infrmatin Wh is in charge f the prject (cntact infrmatin) Wh are the primary cntacts n the prject (cntact infrmatin) When des the mdel have t be dne Get the 15 minute histry Gelgic histry Depsitinal envirnments Structural setting Petrel is a mark f Schlumberger 4801 Wdway Drive, Suite 150W Hustn, TX inf@scminc.cm 2011 SCM E&P Slutins, Inc. 1

2 Field histry Discvery Types f hydrcarbn Onset f drilling and prductin Majr changes in prductin Current status What literature is available n the field r basin What cmpany reprts have been written abut the field What mdels have been built befre Wh built them What prgram was used Hw were they used Were there prblems with thse mdels Why is the field being re mdeled What is the gal f the mdel? Simulatin Vlumes Well planning General understanding f the gelgy Other Hw large an area is t be mdeled? Structure What is the reginal setting Number f hrizns, names, and gelgical relatinships Which hrizns are seismic based Wh did the interpretatin Is that persn(s) available fr questins Is the interpretatin in time r depth Is there a velcity mdel Hw many f the wells were used in the velcity wrk If in depth are the events tied t all tps D the events crrespnd t the hrizns that will be mdeled Is the areal extent f each event similar Is the nise cntent similar fr all events Which hrizns are well based Wh picked the tps and fault cuts Is that persn(s) available fr questins What are the general hrizn trends Any flding f significance r verturned structures What is the ttal thickness and relief f the sectin t be mdeled What is the general character f each zne ischre Always present r missing in sme areas Thick r thin in an area r fllwing certain trends Any minimum r maximum thickness expected Which znes are well behaved and which have prblems Number f faults, types, timing, impact n prductin Which are critical t the mdel s gal Petrel is a mark f Schlumberger 4801 Wdway Drive, Suite 150W Hustn, TX inf@scminc.cm 2011 SCM E&P Slutins, Inc. 2

3 Which are nt imprtant Any Y faults, hw many, and where d they ccur in the sectin Any fault planes riented the same r within 20 degrees f a structure surface Any reverse faults f significant displacement When des faulting ccur, befre, during, r after depsitin Any sub zne structures such as stream channels and what data supprts them Gephysics Are the seismic data (2D r 3D) available fr imprt t Petrel Is there a reasn t imprt the seismic data Is it in depth If nt is the velcity mdel available? If n velcity, are the interpretatins available in bth time and depth If n depth then what is the plan t get t depth Hw gd is the 3D data Can the depsitinal features (channels, sand, pay, ) be seen in the amplitudes Are there particular znes r areas that are better than thers Stratigraphy What is the depsitinal envirnment In general Des it vary fr each zne What are the key rck types What are the reservir rcks What are the nn reservir rcks Hw d they vary in character (thickness, grain size, ) Laterally Vertically Hw persistent are they What are the dminant facies and facies assciatins List the facies General character f each facies Shape and size laterally and vertically Hw persistent are they Rck types and distributin in each facies Reservir r engineering prperties f significance Which facies ccur tgether (assciatin) Typical prprtins Facies psitin in assciatin randm r specific rder (juxtapsed) Assciatin s ccurrence relative t ther assciatins r znes. Petrphysics Which lgs are used Fr general interpretatin Fr picking tps Fr calculating net (list cutffs fr each lg) Fr calculating pay (list cutffs fr each lg) Fr defining facies (list cutffs fr each lg) Tp picks Petrel is a mark f Schlumberger 4801 Wdway Drive, Suite 150W Hustn, TX inf@scminc.cm 2011 SCM E&P Slutins, Inc. 3

4 List them in tp dwn rder What d they represent Which are field wide Which are lcalized Which will be mdeled (structure surfaces built) Which can be ignred Why wuld a tp be missing Did ne r multiple interpreters pick the tps Are there vintages f tps and which is t be used Fluid cntacts What types f fluid cntacts exist Create a list f all cntacts and where they ccur D cntacts vary frm zne t zne D cntacts vary frm fault blck t fault blck Are cntacts flat r tilted Are any cntacts uncertain Is there a range defining highest and lwest levels fr a cntact Hw is the uncertainty t be mdeled Is any special prcessing r cnsideratin needed fr the water cntact Facies Are there facies lgs Is there mre than ne lg and which shuld be used Hw was it built Cutffs frm ther lgs Hand painted frm visual bservatins f ther lgs and data Wh defined the lg and is he available fr questins Prsity Are there prsity lgs What lg was calculated (ttal r effective) Is the same prsity lg available in all wells Are the prsity values all gd r are there prblem wells r znes that shuld be altered r ignred Are there cre prsities Hw are they distributed in the field Hw d cre and lg prsities relate Is there any special cnsideratin t be addressed when mdeling prsity Net t Grss (N:G) Hw was N:G determined Has the methd always been used r are there ther methds Are there ptimistic and pessimistic versins f N:G and hw defined If multiple versins when shuld each be used Is there a N:G lg fr each well Are the N:G values all gd r are there prblem wells r znes that shuld be altered r ignred Is there any special cnsideratin t be addressed when mdeling net t grss Water saturatin (Sw) Petrel is a mark f Schlumberger 4801 Wdway Drive, Suite 150W Hustn, TX inf@scminc.cm 2011 SCM E&P Slutins, Inc. 4

5 Hw was Sw determined Has the methd always been used r are there ther methds Are there alternate methds fr defining Sw If multiple versins when shuld each be used Is there an Sw lg fr each well Are the Sw values all gd r are there prblem wells r znes that shuld be altered r ignred Is there a transitin zne Hw is it defined Is it f significance cnsidering the gal f the mdel Is it f significance cnsidering the cell size (reslutin) f the mdel When can it be ignred Permeability Is there a perm lg Hw was it calculated Des it exist fr all wells Hw is the crrelatin between the pr and perm lgs Is there a pr perm relatinship frm cres r ther surce Can this be cnsidered t represent the entire field Can a relatinship be defined fr each facies Is there a transfrm(s) fr cnverting frm prsity t permeability Are there ther prperties that need t be mdeled Eengineering issues? Des prductin indicate barriers between wells Des prductin indicate a relatinship between pr and perm that differs frm what the data indicates Anything else Are there any uncertainties that must be addressed Structure Hrizns Velcity Faults Ischres Facies Petrphysical Prperties Fluid cntacts Data (where will the data cme frm fr each item) Well data (hw many wells) Well headers (name, X, Y, KB) Deviatin surveys Tps (hw many hrizns) Lgs (usually Las frmat) Cres Seismic data Survey (3D r 2D) Hrizns (hw many) Petrel is a mark f Schlumberger 4801 Wdway Drive, Suite 150W Hustn, TX inf@scminc.cm 2011 SCM E&P Slutins, Inc. 5

6 Interpretatins (time, depth, r bth) Grids (ptinal backup t interpretatins) Faults (hw many) Sticks Plygns Interpretatin Grids (ptinal backup t abve data) Velcity mdel Culture plygns Leases Rivers, rads, etc. Vlumetrics What are vlumes reprted by Fluid Zne Fault blck Lease Facies Distance frm well Units Precisin Sensitivities that need t be run Displays Maps t be generated 3D views t be generated Sectins t be generated Mdel Building Analysis In this step yu utline all the steps yu expect t use t build the mdel. This is fr yur use and desn t have t be fancy but shuld be fairly detailed. This is where yu realize what is really required t d the prject. It is ften useful t have Petrel pen while yu d this and t lk thrugh the prcesses that will be used t remind yu f what must be dne. Use a spread sheet and have ne clumn fr the majr prcess, ne fr the actin t be perfrmed, ne fr the Number f Hurs it will take, and ne fr a Descriptin f the actin. Mre detail is usually gd. Break the table int majr areas such as Data Imprt, Well data Analysis and QC, 2D Gridding, Fault Mdeling, Pillar Gridding, Make Hrizns, Make Znes, etc. A small prtin f this type f spread sheet might lk like the table belw. Yu will find that this analysis table will quickly becme yur guide t the mdeling prcess. By filling this ut yu will have mentally walked thrugh the entire mdeling prcess while cnsidering all aspects f the prject s data, gelgic issues, and gals. When yu are asked t justify yur time estimates yu can refer t this spreadsheet and demnstrate why yu need the extra time t cmplete the wrk. The authrs have fund that this analysis als helps identify time sinks in the prject, and have used this infrmatin t wrk with management and ther team members t mdify the mdeling prcess t reduce r eliminate the time sinks. Petrel is a mark f Schlumberger 4801 Wdway Drive, Suite 150W Hustn, TX inf@scminc.cm 2011 SCM E&P Slutins, Inc. 6

7 Table: Prtin f a spreadsheet used t analyze the wrk and time required t d a prject. Majr Step Actin Hurs Required Discussin Fault Mdeling 100 faults, 50 vertical jins, 2 Y faults, 20 well cuts Build Basic faults faults at 10 minutes each = 1000 minutes = 16.7 hurs Jin faults (vertical) 3 50 jins at 3 minutes each = 150 minutes = 2.5 hurs Jin Y faults 2 2 Y faults at 1 hur each = 2 hurs Tie t fault cuts 2 20 cuts at 5 minutes each = 100 minutes = 1.7 hurs QC and Tuning 9 Tuning f initial fault data and cntinual adjustment f the faults thrughut the mdeling prcess at 5 minutes per fault = 500 minutes = 8.3 hurs Ttal estimate 33 hurs (4.12 days) Pillar Gridding 100 faults, 12 fluid areas, WNW X cell directin Bundary Definitin 1 Define bundary: part faults and part 3D seismic data edge = 1 hur Fault Directin 1 Direct the faults (2) assciated with Y faults and as needed t cntrl the cells (10) = 5 minutes each = 60 minutes = 1 hur Trend Directin 1 Add trends as needed t cntrl cell rientatin and quality (10 trends) at 5 minutes each = 50 minutes = 0.8 hurs Segment Refinement 2 Add trends and directed faults t fully define the fluid areas, 12 areas at 10 minutes each = 120 minutes = 2 hurs QC and parameter tuning Ttal estimate 5 Alter Pillar Gridding parameters, trends, etc. while checking the result in 3D until acceptable. Cntinue adjusting thrughut mdeling prcess. General QC and tuning = 2 minutes per fault plus 2 hurs = minutes = 5 hurs 10 hurs (1.25 days) Petrel is a mark f Schlumberger 4801 Wdway Drive, Suite 150W Hustn, TX inf@scminc.cm 2011 SCM E&P Slutins, Inc. 7

8 Make Hrizns Prpsal The prpsal cntains several parts, each critical t cnvincing the client that yu knw what they want, understand the data and gelgy, have a plan, knw hw lng it will take, and knw what it will cst. Cmmnly included parts might be: Intrductin The intrductin is where yu summarize the entire prject in ne r tw paragraphs. Yu clearly define what the client wants dne, the part f the wrk yu plan t d, and hw lng it will take t d it. Keep this shrt and t the pint. Management needs t be able t read this sectin and knw the scpe f the prject and deliverables withut having t read everything else. If yu d nt wish t mentin csts in this sectin and they are imprtant, then yu shuld say where in the dcument they are discussed r that they will be cvered at anther time. Data/Gelgy In this sectin yu describe the data yu plan t use as input t the mdeling prcess. While ding this yu describe, aspects f the field s gelgy yu cnsider critical t mdeling. Data descriptins might include: The general descriptin: thickness and areal extend f the mdel, number f hrizns, znes, and their stratigraphic relatinships, general rck types, depsitinal envirnment, facies that will be mdeled and grss trends f the layers, faults, and rck bdies. Basic data: the number f wells, tps, fault cuts, and lgs, the fluid cntacts, the number f seismic hrizns and faults as well as whether 3D cubes, 2D lines, velcity mdels, and amplitudes will be used. Special data: transitin znes descriptins fr water saturatin, transfrms that must be prvided fr pr perm mdeling, and ther statistical infrmatin frm this field r neighbring fields critical t building the mdel. Gelgic high pints t mentin might include: baffles r cnduits that impact prductin, gelgical trends bth vertically and laterally that impact prsity, N:G, etc., bundary cnditins that affect the mdel, and s n. Yu are listing these t ensure that 1) yu cnsider them during the mdeling and 2) t shw that the mdeling prcess has the ability t incrprate these gelgic issues (r nt). Gelgic r engineering uncertainties shuld be mentined and, if they are cnsidered significant, yu shuld describe hw yu will handle them. Mdeling The mdeling sectin describes the prduct the client will receive and sme f the key cmpnents in the mdeling prcess. A list f the deliverables ges here r pssibly in a sectin by itself. Any reprts that will be generated shuld be described (a reprt shuld always be generated, utlining all steps and assumptins made when mdeling). If the client is new t mdeling, yu may want t prvide a brief but infrmative utline f the mdeling flw as it relates t this prject (use the Petrel prcess list in the rder they are executed as the utline fr this). The Mdeling Analysis yu did in the previus step culd be included as an appendix and referred t in this sectin. Petrel is a mark f Schlumberger 4801 Wdway Drive, Suite 150W Hustn, TX inf@scminc.cm 2011 SCM E&P Slutins, Inc. 8

9 Time Estimate A table cntaining each mdeling step fllwed by an estimate f time (hurs) it will require is created. This wuld be a subset f the Mdeling Analysis described in the previus sectin. The hurs are summed. If the prject culd be dne quickly by eliminating sme deliverables r steps, then tw tables r tw clumns might be used, ne fr the shrt versin and ne fr the lng. The times are recrded in the same units used fr calculating the cst (hurs if csts are in $/hur, days if cst are in $/day, etc.). The times are ttaled. Yu may wish t include a fudge factr at the bttm t accunt fr the unexpected. This is a multiplier applied t the final hurs. We ften use 1.25, which jumps the hurs up by 25%. It is amazing hw ften that extra time is required t cmplete the prject. The fllwing table is an example f what this time estimate might lk like. Cst Table: Example time estimate fr prject t be mdeled using tw appraches, bth are t be dne. Activity Estimate in hurs Build structural framewrk 24 1 Build average prperty grids 8 1 Cnvert prperty grids t mdel values 8 1 Generate displays and calculate vlumes 8 1 Upscale fr simulatin 8 1 Ttal 56 2 Build facies mdel 24 2 Build ther prperties 24 2 Generate displays and calculate vlumes 8 2 Upscale fr simulatin 8 2 Ttal 64 Sub Ttal 120 Unexpected Factr (25%) 30 Grand Ttal 150 In this sectin the rate yu will charge fr the wrk is listed. If several peple are wrking the prject at different rates then that is explained. The csts fr expenses likely t be incurred are detailed. Yu then prvide a listing f the hurs t be perfrmed by each individual and the expenses they will likely ccur. Add t that any ther csts. If a shrt and lng versin f the prject was described then prvide estimated csts fr each. Turn key prjects, which use a set rate fr all wrk t be dne, are liked by sme clients because they lck in the cst t get a prduct. This apprach can be risky unless yu have really tied dwn the wrk t be dne. It is risky t bth the client and t yu. T the client the risk is that yu have underestimated the csts and might be tempted t push the prject thrugh quickly and d the wrk prly t stay within budget. Risky t yu because, if underestimated, yu will receive less than yur nrmal rate fr the wrk. Whether charges are by turn key r by the hur shuld be clearly stated in this sectin. Petrel is a mark f Schlumberger 4801 Wdway Drive, Suite 150W Hustn, TX inf@scminc.cm 2011 SCM E&P Slutins, Inc. 9