First approach for quantifying undiscovered petroleum initially in place on unconventional resources for a new play in the cretaceous La Luna Formation, at the north of the Middle Magdalena Valley basin, Colombia
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The document discusses methodologies for estimating undiscovered petroleum resources in the La Luna Formation of the Magdalena Basin in Colombia. It includes geological analysis, seismic data interpretation, and petrophysical evaluations to assess the potential of these resources. The findings suggest a significant presence of oil with varying porosity and geological complexity in the region.
![8 DANIEL ROJAS, MARIO PRINCE, ANDREA GALEANO AND CHRISTIAN SÁNCHEZ
Since there are no special core tests available (i.e. core CT-Scan, 3D-SEM), in the last phase of the unconventional petrophysical
analysis, the total porosity (PHIT) is estimated from the Neutron-Density Crossplots after %TOC correction, the water saturation is
calculated (Sw by the dual water model) . The formation water resistivity was assumed as 0.05 Ohm.m@ 75°F (equivalent to
200,000ppm NaCl). The difference between them determines the effective oil filled porosity (OF_Phie).
Y = Vshl[] * ( RwBnd - Rw ) / ( 2 * RwBnd )
SwT = Y + ( (Rw / ( RT * PHIT2
) ) + Y2
)1/2
OF_Phie = PHIT-SwT ……..…………………………………………………………………………………………………………………(2)
Vshl: Volume of shale estimated from Mineralogical interpretation (v/v)
RwBnd: Resistivity of clay bound water (Ohm.m normalized at 75°F)
Rw: Resistivity of free water (Ohm.m normalized at 75°F)
SwT: Total water saturation calculated by the Dual Water Model (v/v)
RT: True formation resistivity curve (Ohm.m)
PHIT: Total Porosity after kerogen correction (v/v)
OF_Phie: Oil filled effective porosity (v/v)
Cutoffs:
Vshl <40%
OF_PHIE>3%
PRMS Methodology
PRMS which stands for “Petroleum Resources Management System” is the standard methodology for Reserves and Resources
assessment, approved and sponsored by the Society of Petroleum Engineers (SPE), the American Association of Petroleum Geologists
(AAPG), among others like the World Petroleum Council (WPC), the Society of Petroleum Evaluation Engineers (SPEE) and the
Society of Exploration Geophysicists (SEG). This methodology was employed for the present study, specifically for the Undiscovered
Petroleum Initially-In-Place, whose key definitions are summarized as follows (Society of Petroleum Engineers SPE et al, 2011):
Undiscovered Petroleum Initially-In-Place (UPIIP). Equivalent to undiscovered resources, is that quantity of petroleum estimated,
on a given date, to be contained within accumulations yet to be discovered.
Uncertainty Categories for Resource Estimates. The range of uncertainty of estimated recoverable volumes may be represented by
either deterministic scenarios or by a probability distribution. When the range of uncertainty is represented by a probability
distribution, a low, best, and high estimate shall be provided such that:
Low Estimate: There should be at least a 90 percent probability (P90) that the quantities actually recovered will equal or
exceed the low estimate.
Best Estimate: There should be at least a 50 percent probability (P50) that the quantities actually recovered will equal or
exceed the best estimate.
High Estimate: There should be at least a 10 percent probability (P10) that the quantities actually recovered will equal or
exceed the high estimate.
Undiscovered Petroleum Initially in Place.
As mentioned previously, the petrophysical evaluation of the Norean-1 well was used for the northern area (Figure 1, North Block).
The Las Lajas-1and Cocuyo-1st wells were used as the analog for the southern portion (Figure 1, South Block). The thicknesses and
effective hydrocarbon filled porosity values from Norean-1, Las Lajas-1, and Cocuyo-1st wells were used as an input of the North and
South blocks. A probabilistic determination of the undiscovered petroleum initially-in-place (UPIIP) was conducted by incorporating
the gross rock volume factored by the net pay thickness in the prospective intervals, oil filled porosity and formation volume factor.
The summary of UPIIP oil volumes for the prospective intervals within the La Luna is presented in Table 1.
Probabilistic distributions & results. As it can be observed in the summary of results (Table 1), the oil filled porosity at the north
area has: p10= 3.46%, p50=5.03% and p90=6.04%, while at the south is p10=3.37%, p50=5.57, and p90=7.14%. The mean net
thickness at north is: 61.83ft, contrasting with a lower one at the south: 42.63ft. The Volumetric factor (Boi) has constant values of:
p10=0.9, p50=0.81 and p90=0.72. The gross rock volume was employed with a normal distribution as well as the volumetric factor,
while it was applied a log normal distribution for the net to gross ratio (Table 1).](https://image.slidesharecdn.com/30-181127202602/85/First-approach-for-quantifying-undiscovered-petroleum-initially-in-place-on-unconventional-resources-for-a-new-play-in-the-cretaceous-La-Luna-Formation-at-the-north-of-the-Middle-Magdalena-Valley-basin-Colombia-8-320.jpg)
First approach for quantifying undiscovered petroleum initially in place on unconventional resources for a new play in the cretaceous La Luna Formation, at the north of the Middle Magdalena Valley basin, Colombia
- 1. ACI Firs unc nort Auto Limit Cate A T T Derecho Este art Este art Abst The a appro 40%, Intro Explo emplo the L Magd metho per ac Area The a 1: Mi these Such this st It wa most Norea IPET st approac convention th of the M ores: Daniel Ro ted. goría: Artículo Técni Tesis Pregrad Tesis Posgrad os de Autor 2013, ACI ículo técnico fue prepa ículo fue seleccionado tract analysis of the oximately 6250 and oil filled p oduction oring for uncon oyed abroad h La Luna Forma dalena Valley odology for the cre of rock exte a of Study area of study is idas, Tisquiram blocks with av wells are: Nor tudy. s necessary to representative an-1 (45km no ch for qua nal resour Middle Ma ojas; Mario P ico X do do PET arado para presentaci o para presentación po La Luna Form 0 barrels of oil porosity of 3-7 nventional reso ave just been a ation has been Basin (MMV e La Luna Form ension are prop s located at the ma-B, Lebrija, T vailable inform rean-1, Cocuyo divide the area wells with rel orth), while the antifying u rces for a agdalena rince; Andrea ión en el XV Congreso or el comité técnico de mation in the n l of Undiscove 7%. ources in Colo applied in the acknowledged VB). By apply mation at the n posed to be as north of the M Tisquirama-A, mation for this s o-1ST and Las a of study in tw levant data (Fig south one was ndiscover new play Valley ba a Galeano and o Colombiano del Petr e ACIPET, basado en northern part o ered Petroleum ombia is still a recent years an d as the main s ying the Petro north of the MM Undiscovered MMV Basin and La Paloma, an study, it was ne Lajas-1 (see F wo in order to gure 1). There s assigned to th red petrol y in the cre sin, Colom d Christian Sá róleo organizado por A información contenida of MMV Basin m Initially in P t an early stag nd the governm source rock an oleum Resour MVB, it was p Petroleum Init d includes the b nd the VMM-2 ecessary to inc ig. 1). The geo define domain fore, the north he domain of th eum initia etaceous mbia ánchez, Petró ACIPET en Bogotá D. a en un resumen envi n under the PR Place. This uni ge, since the te ment’s regulat nd locally as a rces Managem possible to qua tially in Place ( blocks operate 28 block. Given clude neighbor ochemical data ns of petrophys h block was ass he Las Lajas-1 ally in plac La Luna F óleos del Nort C. Colombia, 20 - 22 d ado por el autor(es). RMS methodol it exhibits TOC echnologies an tions have not a naturally frac ment System ( antify probabili (UPIIP). ed by Petronort n the Chuira-1 wells with rele a of Morales-1 sical properties signed the dom well (48km so ce on Formation te S.A.‐ Petro de Noviembre de 201 logy, led to th C of 1.4-5.4% d methodologi been issued ye ctured reservoir (PRMS) resou istic volumes i te, as observed well was the o evant and publ well was not a s, based on the main of the nor outh). n, at the latina Energy 3. he estimation o , Vshale below ies successfully et. Historically r in the Middl urce evaluation in MMbls of oi d in the Figure only one inside lic information available for e distance to th rthernmost wel y of w y y, e n il e . e ll
- 2. 2 Figur confid define study Geol The M cordil strike again forme The w Paleo syncl invert The c Pleist From autho The J startin Arcab depos re 1. Location dential data fro ed to estimate y. logical Settin Middle Magda llera on the ea e-slip system, a nst the Santand ed by the Espir west side of th ozoic Precambr ines product o ted normal fau current sedimen tocene. m the tectonic a ors and can be s Jurassic and Lo ng by the accu buco-Los Sant sited on a mari DANIEL R n of the area o om wells locat domains of pe ng alena Basin (M ast, in the Col and in the east der Massif (fig ritu Santo fault he basin is a ho rian rocks, wh of transpressive ults generally d ntary wedge w and stratigraphi summarized as ower Cretaceou umulation of a tos formations ne environmen ROJAS, MARIO of study, which ted outside, su etrophysical pr MMVB) is an ombian Andes by the Bucaram gure 1). Northw t system, Barre omocline dippi hich gradually e and compres ipping eastwar was progressive ic point of view s follows (figur us (Berriasian) a syn-rift mega s. These units nt at a shallow PRINCE, ANDR h comprises th uch as Norean- roperties for vo intermountain s. The structur manga-Santa M wards, the sed ero D., et al 200 ing eastwards, onlaps westwa ssive tectonics rds, Rolon L., 2 ely eroded by a w, the main ch re 2). ) volcano-sedim asequence whic s are overlaid platform, whic EA GALEANO A he blocks oper -1, and Cocuyo olumetric calcu n basin, flanke ral boundaries Marta fault syst imentary sequ 07. Southward constituted by ards. The east including a w 2004. a succession of haracteristics of mentary rocks ch includes the by Early Cr ch comprises th AND CHRISTIAN rated by Petron o-1ST . The nor ulations. The M d by the Cent are defined in tem, a sinistral uence thins out ds, the basin en y a Jurassic-Cr margin shows west-verging th f unconformiti f this sediment were deposited e Girón or No retaceous calca he Basal Calca MMV N SÁNCHEZ norte, the shar rth (blue) and Morales-1 well tral Cordillera n the west by l strike-slip sys t and finishes ds at the Ibagu retaceous sedim s structural com hrust belt and ies ranging in a tary sequence h d in a tectonica orean Formatio areous and sil areous Group. red block VMM south (magent l data is not av on the west a the Palestina stem that juxta against a pale ue fault system mentary wedg mplexity, with a group of hig age from the P have been iden ally controlled on (Clavijo, J., liciclastic sedi M-28 and non ta) blocks wer vailable for thi and the eastern fault, a dextra aposes the basin ohigh probably . ge overlying th h anticlines and gh-to-low angl Paleocene to th ntified by many fluvial system 1996), and th imentary rock n- e s n al n y e d e e y m, e ks
- 3. FIRS FOR Shallo impor Luna abund outcro Galem A seq Umir cycle The L lacust late P forme Figur of Pet Seism Over exten ST APPROACH R A NEW PLAY ow to deep m rtant world sea a Formation c dant laminated op. In Colomb mbo, which ran quence of uppe r and the Lisam environment. La Paz, Esmer trine clastic en Pliocene or mo ed on an enviro re 2. Generaliz tronorte. mic interpre 1600 kilomete nsion and fault Pet NW FOR QUANTIFY IN THE CRETAC marine sedimen a level change consists of thin d and finely dis bia, Morales e nge in age from er Cretaceous ma formations, raldas, Mugros nvironment, for ore probably e onment of coal zed regional Str tation ers of 2D and o analysis of the ronorte’s blo N YING UNDISCOV CEOUS LA LUNA ntary deposits s represented b n bedded and sseminated org et al., 1958, di m early Turonia Maastrichtian was deposited sa, Colorado a rmed during th arly Pleistocen lescing alluvial ructures and St over 350 kilom e La Luna Form ocks SE NW VERED PETROL A FORMATION, from Albian by the Simití a laminated, den ganic matter, w ivided the La an to Santonian to Paleocene d during the firs and Real form he progressive u ne age, was de l fans that were tratigraphy of t meters of 3D se mation. The av LEUM INITIALLY AT THE NORTH through Camp and the La Lun nse, dark gray with ellipsoidal Luna Formati n. age deep mari st phases of th mations, from E uplift of the Ce eposited uncon e deposited in t the north of M eismic data ava vailable sonic, Y IN PLACE ON H OF THE MIDD panian age we na formations. to black colo l concretions th ion into three ine siliciclastic e compression Eocene to Mio entral and East nformably on t the Magdalena Middle Magdale ailable were in check shot and UNCONVENTIO DLE MAGDALEN ere deposited According to ored limestones hat allow to re members nam c to transitiona nal deformation ocene age, we tern cordilleras the Real Grou a River Valley. ena basin, acco nterpreted, in o d Vsp logs wer ONAL RESOURC NA VALLEY BAS on a platform Hedberg and s and calcareo ecognize the fo med as Salada, al sediments, r n in a transgres re deposited in s. Then the Me up and older st . ording to the ge order to provide re used to tie th SE CES 3 IN, COLOMBIA m influenced by Sass, 1937, th ous shales, with ormation in any Pujamana and recorded by th ssive-regressiv n a fluvial and esa formation o trata. The latte eological mode e the geometry he top and bas y e h y d e e d of er el y, e
- 4. 4 of the overly There disrup Luna area o Time veloc Simit the is accur provi Figur Form reflec Rock appro the ar e unit. The top ying Umir Fo efore, the la Lu pted by reverse Fm. is tied to of study (Figur to depth conv cities ranging f tí isochronous m sopach values a racy of the pick des a quantific re 3. Example mation, at the s ction is a strong k volumes. The oximately 1,80 reas where the 0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 2600 2800 3000 3200 3400 3600 3800 4000 4200 4400 999 00.0 N DANIEL R of the La Luna ormation, wher una top refecti e high angle fa the underlying re 3). version was don from 8720 ft/se mapping using at well ties. Th ked events. The cation of gross e of the seism south of the a g high amplitud e gross thickne 0 feet (Figure La Luna Fm. i 4050 2025.5 4100 2050.5 NW ROJAS, MARIO a Formation is re there is an ion is a strong aults and fractu g unit Simití F ne using averag ec at the north g an average in is was carried erefore, based rock volume th mic expression area of study ( de wave only d ess of the La L 4). Given the is buried at dep 4150 2075.5 4200 2100.5 PRINCE, ANDR revealed by th important imp high amplitud ured zones, wh ormation whic ge velocity fro h to 8820 ft/sec terval velocity out as a means on this structu he La Luna sec of the top (br (Tisquirama A disrupted by so Luna in the thr absence of fur pths greater tha 5 4250 2125.5 4300 2150.5 PC-1981 EA GALEANO A he seismic expr pedance chang de wave that ca hich are freque ch was observe m Chuira-1 we c to the south. y of 8541 feet/s s of checking th ural interpretati ction (see Figu right green) an A Block). Inter ome faults and ee key wells th rther data regar an 4.000ft, to e 5 4350 2175.5 4400 2200. 1-08.MIG_i95%.0 AND CHRISTIAN ression of the c ge usually from an be defined ent in the area ed in the Mora ell VSP and La The isopach m second, and wa he validity of t ion the extensio ure 4). For each nd the base (S rpreted Seismi fractured zone hat had penetr arding biodegra ensure the prese 0 .5 4450 2225.5 450 2250 CO EO LO UM LA SIM RO N SÁNCHEZ contact betwee m very low to as a continuou of study (see F ales-1 well, and as Lajas-1 chec map (Figure 4) as computed an the isochronou on and thickne h block a calcu Simití Fm. in ic line PC198 es. rated completel adation, it was ervation of hyd 00 0.5 4550 2275.5 46 230 OLORADO FM. OCENO DISC. OWER LISAMA MIR FM. A LUNA FM. MITI FM. OSABLANCA FM en this unit and o high amplitu us and coheren Figure 3). The d was also corr ck shot survey ) was based fr nd the magnitu us values and co ess information ulations of this w dark green) o 81-08. The La ly the La Luna assumed to ta drocarbons. 0 200 400 600 800 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400 420 440 00 0.5 4650 2325.5 SE M. d the base of th udes reflection nt horizon, only e base of the L related over th y using differen rom La Luna to ude compared to onsequently th n, its integration was generated of the La Lun Luna Fm. top a Fm., average ake into accoun 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 e n. y a e nt o o e n . a p s nt
- 5. FIRS FOR Figur Fm (f Geoc Based thickn (type 1 wel avera (0,68 (avera Tmax from Petro Three Cocu and c specia The p C.H. contin ST APPROACH R A NEW PLAY re 4. Results o feet TVDSS). R chemical cha d on the availa ness is: very ri II and mixed I ll the 520ft of t age from 16 cu % of Vitrinite age of 2,7% fr x.). Finally, in t 73 cutting sam ophysics e wells were em uyo-1ST , respect core tests to ba al logs nor adv petrophysical in et al, 2010, wh nuous curves o FOR QUANTIFY IN THE CRETAC of the seismic i Right: Gross Is aracterizatio able core tests o ich in terms of II & III Keroge thickness (this utting samples) e Reflectance). om 150 cutting the Cocuyo-1S mples); oil pron mployed for th tively. The dat sic geochemica vanced core tes nterpretation w hich basically of properties th YING UNDISCOV CEOUS LA LUNA interpretation o sopach Map of n of the La L of the analyzed quantity of tot en), and it is cu well perforated ); mostly oil pr . In the Norea g samples); oil ST well, the 2,1 ne kerogen (I an he petrophysica ta set was limit al data (Total O sts such as X-R was conducted integrates the hat allowing ev VERED PETROL A FORMATION, of the La Luna f the La Luna F Luna Formati d wells, it was tal organic carb urrently at the e d only the upp rone (II and m an-1 well, from l prone (mainly 125ft of thickn nd II type), and al analysis, cov ted to a conven Organic Carbo Ray Diffraction by the applica point-to-point aluating the po 10 Km LEUM INITIALLY AT THE NORTH a Fm in the are Fm to Simití Fm ion observed that bon (%TOC av early oil windo er part of La L mixed II & III t m the 1,716 ft y I and II Kero ness the La Lun d it is also in in vering from no ntional Quad-C on %TOC, Vitr n (XRD) or sha ation of the Pa data from geo otential as an u Y IN PLACE ON H OF THE MIDD ea of study. Le m (feet TVD). the La Luna F verage of 3,3% ow generation Luna Fm) it exh type), and it is ft of thickness ogen type), and na Fm is: very nitial window o orth to south th Combo (Gamm rinite Reflectan ale porosity/satu ssey’s method ochemical core unconventional UNCONVENTIO DLE MAGDALEN eft: Structural m Formation in L %from 72 cuttin (0,62% of Vitr hibits: very goo s also in the in it shows: ver d it is as well in good amounts of oil generatio he area of stud ma Ray, Resisti nce %Ro and P turation were a d (Passey, Q.R. e tests to the e reservoir. ONAL RESOURC NA VALLEY BAS map at the top Las Lajas-1 we ng samples); o rinite Reflectan od quantities o nitial phase of ry good quant n initial oil win s of %TOC (av on (438°C Tma dy: Norean-1, L ivity, Nuclear a Pyrolysis Rock available for thi ., et al 1990) a lectric logs in 10 Km CES 5 IN, COLOMBIA of the La Lun ll in 1,780 ft o il prone mainly nce). In Chuira of %TOC (2,3% the oil window tities of %TOC ndow of (435°C verage of 2,75% ax.). Las Lajas-1 and and Sonic logs k Eval). Neithe is study. and Sondergeld order to obtain a of y a- % w C C % d s) er d, n
- 6. 6 Litho conve grain Gamm cross- tests. marls Out o recrys Figur Color of the calcar Total (Equa calibr of vit Based 1ST ∆Log TOC= RT: T RTBas DT: C DTBas ∆Log TOC: LOM Oil F organ them. gener ology. The lith entional petrop density (DGA ma Ray Log (S -plots were co From this ana s and black sha of the three wel stallization (se re 5. Lithology red points repr e crossplots, su reous due to th l Organic Ca ation 1) in wh ration with geo trinite reflectan d on this analy with an averag gR=Log10(RT / =(∆LogR)*10( True formation seline: RT readin Compressional seline: DT readin gR: Amount of : Calculated To M: Level of mat Filled Porosity nic matter of th . The values of ration window. DANIEL R hological com physical cross- A), and appare See Fig 5). Fo nfirmed qualit alysis it can be ales. Some con lls, Norean-1 e e Figure 7). y crossplots (U esent the volum uggesting the p he use of Barite arbon (%TOC hich the effect ochemical core nce as equal to ysis, the richest ge TOC of appr / RTBaseline)+0.0 (2.297-0.168*LOM) … n resistivity cur ngs where it ma l travel time cu ngs where it m f separation bet otal organic ca turity of the org (OF_Phie) an he La Luna Fm f vitrinite reflec . ROJAS, MARIO mposition of th -plots based on ent volumetric or this study, i tavely only wit concluded that ntent of silt siz exhibits in gene UMA vs. DGA me of shale est predominance o e in the drilling C). The conten of kerogen on e data. The leve nine (9) for No t well in terms roximately 3.5 02*(DT-DTBase ………………… rve (Ohmm.m) atches DT curv urve (µsec/ft) matches RT curv tween the overl rbon content in ganic matter nd Water Satu . is turning into ctance (%Ro= PRINCE, ANDR he three analy n nuclear logs c photoelectric it is assumed t th the ditch sam t the three wel zed quartz part eral, a higher d vs. Vshl), sho timated from G of limestones a g mud, affectin nt of organic m n resistivity an els of organic m orean-1 and eig s of organic ma 5%, and Norean eline) ……………… ve at the approp ve at the appro laid curves (RT n wgt%. uration (Sw). o hydrocarbon 0.65-0.72) and EA GALEANO A yzed wells wa (Neutron, Den factor (UMA the volume of mples descript ls, the La Luna icles is commo development of wing the mine Gamma Ray lo and marls over ng the readings matter %TOC nd porosity log maturity or me ght point five ( atter is Las Laj n-1 with a TOC ……………… priate scale (O opriate scale (µ T and DT). Geochemical c s, implying tha d the Pyrolysis AND CHRISTIAN as estimated b nsity and Phot A) are calculate clay (Vcl) as tion, due to the a Fm. exhibits on as well as t f limestones w eral compositio og. Most of poi r silica. The cro of the Photoel C was determin gs (neutron-den etamorphism (L (8.5) for the w ajas-1 (TOC av C close to 1.5% ………………… Ohmm.m). µsec/ft). core tests of th at both primary (Tmax= 435-4 N SÁNCHEZ based on elec toelectric Fact ed in addition equal to the v e absence of X alternating lay the recrystalliz which could cor on of the analy ints tend to be ossplot of the C lectric Factor a ned by Passey nsity and soni LOM) were sel ells Las Lajas- verage~ 5%), f % (Figure 7). ……………… he three wells s y porosity and 438°C), indicat ctric logs, by tor), from whic n to the Vshl olume of shale X-Ray Diffracti yers mudstone zation of muds rrespond to a h yzed wells in th located in the Cocuyo-1ST (l and Density log y’s “Delta Log ic) is quantifie lected accordin -1 and Cocuyo followed by the ……………… suggest that in kerogen can be te the beginnin employing th ch the apparen estimated from e (Vshl). Thes ion (XRD) cor s, wackestones tones (micrite) higher degree o he La Luna Fm calcareous are left) looks mor gs. g R” techniqu ed based on th ng to the value -1ST (Figure 6) e well Cocuyo ………….(1) this area, the e filled with ng of the oil e nt m e e s, ). of m. a e e e es ). o-
- 7. FIRS FOR Figur accor gener Figur with select ST APPROACH R A NEW PLAY re 6. Parameter rding to the val ration and destr re 7. Petrophys Sonic and Re ted based on FOR QUANTIFY IN THE CRETAC rs employed fo lues of vitrinite ruction (modif sical profiles o sistivity logs, NOREAN‐1 YING UNDISCOV CEOUS LA LUNA or estimating th e reflectance % fied from Dow, of the analyzed and calibrated VERED PETROL A FORMATION, he thermal mat %Ro (modified , 1977) d wells, based o d with core TO LA LEUM INITIALLY AT THE NORTH turity of organi from Passey et on Passey’s me OC data from AS LAJAS‐1 Y IN PLACE ON H OF THE MIDD ic matter. Left t al 1990 in So ethodology. Th Norean-1 and UNCONVENTIO DLE MAGDALEN : Estimation of ondergeld, 2010 he %TOC is ca d Cocuyo-1ST C ONAL RESOURC NA VALLEY BAS f the level of o 0). Right: Zone alculated based wells. Net Pa COCUYO‐1ST CES 7 IN, COLOMBIA rganic maturity es of petroleum d on DeltaLogR ay intervals ar y m R e
- 8. 8 DANIEL ROJAS, MARIO PRINCE, ANDREA GALEANO AND CHRISTIAN SÁNCHEZ Since there are no special core tests available (i.e. core CT-Scan, 3D-SEM), in the last phase of the unconventional petrophysical analysis, the total porosity (PHIT) is estimated from the Neutron-Density Crossplots after %TOC correction, the water saturation is calculated (Sw by the dual water model) . The formation water resistivity was assumed as 0.05 Ohm.m@ 75°F (equivalent to 200,000ppm NaCl). The difference between them determines the effective oil filled porosity (OF_Phie). Y = Vshl[] * ( RwBnd - Rw ) / ( 2 * RwBnd ) SwT = Y + ( (Rw / ( RT * PHIT2 ) ) + Y2 )1/2 OF_Phie = PHIT-SwT ……..…………………………………………………………………………………………………………………(2) Vshl: Volume of shale estimated from Mineralogical interpretation (v/v) RwBnd: Resistivity of clay bound water (Ohm.m normalized at 75°F) Rw: Resistivity of free water (Ohm.m normalized at 75°F) SwT: Total water saturation calculated by the Dual Water Model (v/v) RT: True formation resistivity curve (Ohm.m) PHIT: Total Porosity after kerogen correction (v/v) OF_Phie: Oil filled effective porosity (v/v) Cutoffs: Vshl <40% OF_PHIE>3% PRMS Methodology PRMS which stands for “Petroleum Resources Management System” is the standard methodology for Reserves and Resources assessment, approved and sponsored by the Society of Petroleum Engineers (SPE), the American Association of Petroleum Geologists (AAPG), among others like the World Petroleum Council (WPC), the Society of Petroleum Evaluation Engineers (SPEE) and the Society of Exploration Geophysicists (SEG). This methodology was employed for the present study, specifically for the Undiscovered Petroleum Initially-In-Place, whose key definitions are summarized as follows (Society of Petroleum Engineers SPE et al, 2011): Undiscovered Petroleum Initially-In-Place (UPIIP). Equivalent to undiscovered resources, is that quantity of petroleum estimated, on a given date, to be contained within accumulations yet to be discovered. Uncertainty Categories for Resource Estimates. The range of uncertainty of estimated recoverable volumes may be represented by either deterministic scenarios or by a probability distribution. When the range of uncertainty is represented by a probability distribution, a low, best, and high estimate shall be provided such that: Low Estimate: There should be at least a 90 percent probability (P90) that the quantities actually recovered will equal or exceed the low estimate. Best Estimate: There should be at least a 50 percent probability (P50) that the quantities actually recovered will equal or exceed the best estimate. High Estimate: There should be at least a 10 percent probability (P10) that the quantities actually recovered will equal or exceed the high estimate. Undiscovered Petroleum Initially in Place. As mentioned previously, the petrophysical evaluation of the Norean-1 well was used for the northern area (Figure 1, North Block). The Las Lajas-1and Cocuyo-1st wells were used as the analog for the southern portion (Figure 1, South Block). The thicknesses and effective hydrocarbon filled porosity values from Norean-1, Las Lajas-1, and Cocuyo-1st wells were used as an input of the North and South blocks. A probabilistic determination of the undiscovered petroleum initially-in-place (UPIIP) was conducted by incorporating the gross rock volume factored by the net pay thickness in the prospective intervals, oil filled porosity and formation volume factor. The summary of UPIIP oil volumes for the prospective intervals within the La Luna is presented in Table 1. Probabilistic distributions & results. As it can be observed in the summary of results (Table 1), the oil filled porosity at the north area has: p10= 3.46%, p50=5.03% and p90=6.04%, while at the south is p10=3.37%, p50=5.57, and p90=7.14%. The mean net thickness at north is: 61.83ft, contrasting with a lower one at the south: 42.63ft. The Volumetric factor (Boi) has constant values of: p10=0.9, p50=0.81 and p90=0.72. The gross rock volume was employed with a normal distribution as well as the volumetric factor, while it was applied a log normal distribution for the net to gross ratio (Table 1).
- 9. FIRST APPROACH FOR QUANTIFYING UNDISCOVERED PETROLEUM INITIALLY IN PLACE ON UNCONVENTIONAL RESOURCES 9 FOR A NEW PLAY IN THE CRETACEOUS LA LUNA FORMATION, AT THE NORTH OF THE MIDDLE MAGDALENA VALLEY BASIN, COLOMBIA OIL RESERVOIR PARAMETERS AREA La Luna North La Luna South Total MEAN AREA: acre 39206.00 170174.00 209380.00 Mean Gross Thickness: ft 262.67 120.50 191.58 Mean Net Thickness: ft 61.83 42.63 52.23 MEAN OIL FILLED POROSITY (%) 4.68 4.80 4.74 P90 6.04 7.14 6.59 P50 5.03 5.57 5.30 P10 3.46 3.37 3.41 1/Boi (vol/rvol) 0.81 0.81 0.81 P90 0.72 0.72 0.72 P50 0.81 0.81 0.81 P10 0.90 0.90 0.90 GROSS LEASE UNDISCOVERED PETROLEUM‐INITIALLY‐IN‐PLACE (MMBBL) 1373.70 4878.90 6252.60 Low Estimate (P90) 515.40 2127.50 2642.90 Best Estimate (P50) 1140.70 4166.00 5306.70 High Estimate (P10) 2085.90 6714.00 8799.90 MEAN RESOURCE CONCENTRATION (MBBL/ACRE) 35.04 28.67 29.86 Table 1. Summary of input petrophysical and volumetric calculations of the La Luna Fm., employed for the probabilistic calculation of resources (UPIIP), in the area of study (north and south blocks). Despite the thickness of the net pay intervals is slightly thicker in the northern area (Net Pay 62ft vs. 43ft), the remarkably greater extension of the southern area influences directly the bigger volumes and therefore the estimated resources (4879MMBO vs. 1374MMBO, respectively), regardless of its higher density of resources (35 Mbbl/Acre vs. 29 Mbbl/Acre). The results of this study exhibit the great potential of the La Luna Fm. in the North of the MMV basin, with a resource concentration of close to 30000 barrels of oil per acre, which represents approximately 6250 million barrels of undiscovered petroleum initially in place. Conclusions and Recommendations The assessment of the La Luna Formation at the north of Middle Magdalena Basin specifically in Petronorte’s blocks reveals an unconventional potential of approximately 6250 million barrels of undiscovered petroleum initially in place (UPIIP). In the area of study, this unit exhibits the unique characteristics of amount, quality and thermal maturity of organic matter, to possess an average resource concentration of 30000 barrels of oil per acre. This study is part of the many recent efforts to analyze the La Luna Fm. as an unconventional reservoir in Colombia. However, since this is one of the first published quantification of such potential, the authors expect to encourage others to continue evaluating this subject. Although the ideal set of electric logs and core tests was not available for this study, it was possible to obtain a reliable approach to the quantification of unconventional resources of the La Luna Formation, by the employment of industry’s proven techniques, like the Passey’s method to tie geochemical rock properties to the electric logs and thus allowing the definition of volumetric parameters.
- 10. 10 DANIEL ROJAS, MARIO PRINCE, ANDREA GALEANO AND CHRISTIAN SÁNCHEZ The availability of a full set of geochemical and geomechanical core tests is a key factor to decrease to decrease the uncertainty of assumptions to assess for resources and reserves for instance, the minimum burial depth for oil biodegradation, the precise mineralogy composition and brittleness for fracturing design, etc. References 1. Barrero, D., Pardo, A., Vargas, C & Martínez, J. 2007. “Colombian Sedimentary Basins: Nomenclature, Boundaries and Petroleum Geology, a New Proposal”. ANH, Bogotá. p.92. 2. Rolon L. 2004. “Structural Geometry of the Jura-Cretaceous Rift of the Middle Magdalena Valley Basin-Colombia”. Msc. Tesis. West Virginia University. p.3. 3. Clavijo, J., 1996. “Mapa geológico de Colombia”, Plancha 75 – Aguachica. Ingeominas. Memoria explicativa, pp. 1-48. Bucaramanga. p.1-48 4. Hedberg, H. D. and Sass, L. C., 1937. “Synopsis of the geologic formations of the western part of the Maracaibo basin, Venezuela”, Bol. Geol. y Min. (Venezuela), 1(2-4): p.73-112. 5. Morales, L.G. and the Colombian Petroleum Industry, 1958. “General Geology and Oil occurrences of Middle Magdalena Valley, Colombia”, in Habitat of Oil: A Symposium (L.G.Weeks ed.), Tulsa, AAPG Bulletin: p.641-695. 6. Passey, Q.R., S. Creaney, J.B. Kulla, F.J. Moretti, and J.D. Stroud, 1990. “A Practical Model for Organic Richness from Porosity and Resistivity Logs”. AAPG Bulletin (v.74 /12). p.1777-1794. 7. Sondergeld, C. H., Newsham, K. E., Comisky, J. T., Rice, M. C., and Rai, C. S., 2010, “Petrophysical Considerations in Evaluating and Producing Shale Gas Resources”, SPE 131768, SPE Unconventional Gas Conference, Pittsburgh, Pennsylvania 23-25, 2010. 8. Society of Petroleum Engineers SPE, American Association of Petroleum Geologists AAPG, World Petroleum Council WPC and Society of Petroleum Evaluation Engineers SPEE, 2011. “Guidelines for Application of the Petroleum Resources Management System (PRMS)”. Society of Petroleum Engineers SPE. November, 2011. p.2-30. Equations 1. Passey’s Delta Log R, based on sonic and resistivity logs. Passey, Q. R., et al, 1990. 2. Dual Water Model. Passey et al 1990. Passey, Q. R., et al, 1990.