Integrated Contract

Integrated Contract
1

Content
Integrated Contract
Introduction ............................................................................................................................... 3
Basin Description ...................................................................................................................... 5
Main Features ........................................................................................................................... 9
History of Exploration and Development ........................................................................ 15
Production by Field and Reserves .................................................................................... 18
Infrastructure and Hydrocarbons Handling ................................................................... 19
Drilling History .......................................................................................................................... 21
2

Introduction
The Miahuapan block is located in the Northwest part of the “Activo Integral Aceite
Terciario del Golfo” surface, covering an area of 128 Km 2 ; it is 20 Km NW of Poza Rica,
Veracruz.
Location of Block Miahuapan
Geologically, it is located in the South of the Tampico - Misantla basin. The principal field
in this area is Miahuapan, which was discovered in 1948; gas and oil shows were observed
in the formation Tamabra, in the well Miahuapan-5 with 2,326m depth.
In this block 54 wells has been drilled, 16 are close, 27 plugged and 11 open. Maximum
production was 1,080 bpd oil with 10 open wells in June, 1976; now (30/06/12)
production is 348 bpd oil, its cumulative production is 42.256 Mbls oil and 5.7MMpc gas.
Oil type is light crude, with a density of 33° API the bottom pressure measured recently in
the well Jiliapa-71 varies between 78 and 150 Kg/cm 2 . The existing production system in
the area is mechanical pump. Average depths of the deposits are 1,900 in Tertiary and
2,380m for Mesozoic.
During drilling of the exploratory wells in the Mesozoic formations: Tamabra, Tamaulipas
Superior, Tamaulipas Inferior, Pimienta y Tamán, light to moderate gas shows occurred; in
the channel samples and cores, oil impregnations were observed.
3

By PVT analysis of different Wells from the formations mentioned, from the Paleocanal
de Chicontepec area, the following information is obtained:
• Coyula-1 Well (located southwest at 8.5 Km from area):
Formation Tamaulipas Superior: 42.2 °API Oil, gas solubility at initial pressure relationship
(Rsi) of 221.60 m 3 /m 3 , Oil Volume Factor (Bo) 1.6629 m 3 /m 3 and a saturation pressure (Pb)
de 217.00 Kg/cm 2 .
• Presidente Miguel Alemán-772 Well (located southeast at 31 Km from area):
Formation Tamaulipas Inferior: 35.7 °API Oil, gas solubility at initial pressure relationship
(Rsi) of 179.50 m 3 /m 3 , Oil Volume Factor (Bo) de 1.6270 m 3 /m 3 and a saturation pressure
(Pb) de 215.20 Kg/cm 2 .
• Caviar-1 Well (located northeast at 160 Km from area):
Formation Pimienta: 15.74 °API Oil, gas solubility at initial pressure relationship (Rsi) of
33.28 m 3 /m 3 , Oil Volume Factor (Bo) de 1.1659 m 3 /m 3 and a saturation pressure (Pb) de
106.16 Kg/cm 2 .
• Furbero-106 Well (located southeast at 25 Km from area):
Formation Tamán: 37.11 °API Oil, gas solubility at initial pressure relationship (Rsi) of
179.60 m 3 /m 3 , Oil Volume Factor (Bo) of 1.8138 m 3 /m 3 and a saturation pressure (Pb) of
175.10 Kg/cm 2 .
• Jiliapa-71 Well (located north at 4.5 Km from area):
Formation Tamabra: 34.5 °API Oil, gas solubility at initial pressure relationship (Rsi) of
120.00 m 3 /m 3 , Oil Volume Factor (Bo) de 1.4234 m 3 /m 3 and a saturation pressure (Pb) de
161.00 Kg/cm 2 .
4

Basin Description
Integrated Contract
The Tampico - Misantla basin is located in Eastern Mexico and it spans from Southern
Tamaulipas to the central part of the State of Veracruz, along with a small part of the east
side of the States of San Luis Potosí, Hidalgo and North of Puebla, down to the 200-m
isobaths of the Gulf of Mexico's continental shelf.
Location of Tampico – Misantla Basin.
The crystalline basement is formed by igneous and metamorphic rock, their ages ranging
from Permian to the middle Jurassic. In the sedimentary column of the Tampico-Misantla
province, the following tectono-sequences are identified:
5

First tectono-sequence (Synrift). Started in the Triassic (250Ma), with the deposition of
continental clasts from alluvial and fluvial environment with some lava flowed from the
Huizachal formation, from the late Triassic age (Noriense-Retiense), over crystalline and
metamorphic basements, later the Huayacocotla formation from the Lower Jurassic
(Hettangiano-Pliensbachiano) was deposited, and it is a sandstones and shale sequence,
from transgressive oceans. By the middle Jurassic, continental conditions were restored,
with Clasts from the Cahuasas formation being deposited, by the end of this period, a new
marine transgression commenced, and favored the deposition of oolithic limestone for
the Huehuetepec formation (Bathonian), and sandy limestone with bioclasts and ooliths
for the Tepexic formation (Callovian), which were overlain by calcareous and
carbonaceous shale with plenty of oGORnic matter, from the Santiago formation
(Oxfordian), deposited on constrained, low-energy seas; as the marine transgression
moved forward, carbonate ramps developed around the basement highs - inside and on
the edge of the former, sandy-clayey limestone and oolithic limestone from the San Pedro
and San Andrés formations were deposited, (Kimmeridgian), respectively, and their lateral
equivalents toward deeper waters, namely, the clayey limestones with scarce bioclasts
and oolites (Chipoco formation) and basin black clayey limestones (Tamán formation).
The transgressive sea conditions continued so that during the Tithonian-Portlandian, a
maximum flooding surface would occur, with most of the basement highs being left in
underwater conditions. During that time, clayey-carbonaceous limestones were
deposited, (rich in oGORnic matter) from the Pimienta formation, from a relatively-deep-
water environment, which is present throughout the region and only in the parts
emerging from the basement, which were under coastal and/or shoreline conditions; La
Casita formation was deposited, which is constituted by glauconitic sandstones.
Passive Margin Tectono-sequence. The marine transgression carried on and ultimately
flooded all of the basement highs, it deposited on the internal parts, limestones and
dolomites, while on the edges, the oGORnic-reefal growths development commenced. At
the same time, and due to the thermal subsidence, the lower areas deepened, giving rise
to deep sea basins, where the three members of the Tamaulipas Inferior formation were
deposited (calcarenithic member, bentonitic member and creamy limestone member)
corresponding to the Berriasian-Barremian age. During the Aptian stage, the Otates
horizon formation deposition occurred, which is considered to be a condensed sequence.
During the Albian, along the entire Tuxpan platform a reef edge, roughly 1400 m thick,
which gave rise to lagoon facies on the inside of the platform, whereas for the reef front,
the Tamabra formation, featuring proximal, mean and distal slope facies, developed due
6

to the reefal denudation, and changes facies with the chalky limestone Tamaulipas
Superior formation.
By the end of the Cenomanian, the platform remained under subaerial conditions by a
regressive marine pulse, which was followed by a new transgressive event allowing the
deposition both in lagoon facies and in the mean, distal slope and basin of the Turonian
Agua Nueva (black clayey limestones with black shales interbeddings), Coniacian-
Santonian San Felipe (greenish-grey clayey limestone with abundant olive green bentonite
interbeddings) and Campanian-Maastrichtian Méndez (clayey limestones and green/red
marls) formations; the period of this tectono-sequence ended with the deposition of the
last formation.
Eventos
Tectónicos
Ambientes
sedimentarios
Geologic column for the Tampico-Misantla basin with reservoir rock, source rock
(unconventional reservoirs), tectonic events and sedimentary environments.
The foreland basin tectono-sequence is characterized by the onset of the Sierra Madre
Oriental's (SMO) uplift, which gave rise to a greater contribution of terrigenous material
7

sediments; these marine cenozoic depositions were originally defined as Tampico-Misantla
Basin by López-Ramos (1956).
The ongoing uplift of the SMO left very narrow coastal plains and continental shelves,
hence the coastal systems would go from a prodelta to a slope, and where the transport of
sediments by means of turbidity currents prevailed, there would be flow of debris and
landslides, which would produce deposition of submarine fans at the bottom of the
seafloor (basin), overlapping each other and generating submarine erosion during their
development.
By the end of the Cenozoic, deltaic environments prevailed.
Tuxpan
Poza Rica
Tecolutla
Tertiary Sedimentary model (Paleogene and Neogene). Note that delta environments
were deposited above the Chicontepec formation
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Main Features
Integrated Contract
The main producing formation of this block is formed by Mesozoic formations; cumulate
production for this area is 3,400 mbls, while in Chicontepec there’s a cumulate production of
42.25mbls. The producing formations are Tamabra, Tamaulipas Superior, Tamaulipas Inferior,
and Tamán from Cretaceous, Medio, Inferior and Jurassic Superior, respectively.
The reservoirs in this area are located in combined, structural (anticlines with subtle dips
with four-direction closure) and stratigraphic traps.
This block has 51 wells from Mesozoic, 29 of them have production records from that
reservoir; 26 of them belong to Tamabra with a production range between 25 and 673 bpd,
one well in Tamaulipas Superior with 88 bpd, one in Tamaulipas Inferior - Pimienta with 1,849
bpd and one well in Tamán with 195 bpd.
Some examples of producing wells in Mesozoic are: Centurión-1 from Tamabra, Marques-1
from Tamaulipas Superior, Zapotalillo-2 from Tamaulipas Inferior-Pimienta and Papatlarillo-102
from Tamán. 29 wells from Mezosoic show oil impregnation both in cores and cuttings from
San Felipe, Tamabra, Tamaulipas Superior, Tamaulipas Inferior, Pimienta and Tamán
formations, there are also 11 wells which showed gas while drilling in the Brecha, Méndez,
Agua Nueva, Tamabra, Tamaulipas Superior, Tamaulipas Inferior and Tamán formations.
In the Centurión-1 well, no oil or gas shows were detected while drilling, 2 cores were cut in
Tamabra formation with poor oil impregnation. For Tamabra formation, poor viscosity oil and
good light oil impregnation was observed in the cuttings.
Two production tests were conducted in the Tamabra formation, the first test in the 2267-2277
m interval, it exhibited no flow, performed a survey, displacing stained water (95-100% water),
the test concludes and the interval is plugged; the second production test was conducted in the
2179-2189 m interval, performed acid treatment, well is open and displacing oil and gas with
little water, with a production of 673 bpd oil, 1.2% water and GOR: 99 m 3 /m 3 .
In the Marques-1 well, gas shows were observed in the Agua Nueva, Tamabra, Tamaulipas
Superior and Tamaulipas Inferior formations, decreasing the mud density from a range of 1.47
to 0.89 gr/cc in a period from 15 to 90 minutes. One core was cut from the Tamaulipas Inferior
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formation, with poor oil impregnation in the stratigraphic plains. Light oil impregnation was
found in the cuttings from San Felipe and Tamabra formations and light oil impregnation and
asphalt were found in the Tamaulipas Inferior formation.
In the well Zapotalillo-2, no oil or gas shows were detected while drilling. Two cores were cut
in the formation Tamabra with little oil stains and a few traces of oil. fractures filled with
asphalt, viscous oil and black residual oil were observed in the cuttings from Tamabra,
Tamaulipas Superior, Inferior y Pimienta formations.
Two open-hole tests were made in with acid treatment in the Tamabra formation (1),
recovering gasified mud with traces of oil and the other one in the Inferior-Pimienta formation
(1), recovering oil, gas and little water, resulting in a production of 1,849 bpd oil, water 0.1%,
gas 1.9 mmpcpd, and GOR: 186 m 3 /m 3 .
Two production tests with acid treatment were conducted in the Tamaulipas Superior and in
Tamabra formations, flowing 100% water in the first one and flowing water with oil traces in
the second one.
In the well Papatlarillo-102, strong gas shows were observed while drilling in the Tamán
formation. Five cores were cut, in the formation Tamabra (3) with regular oil impregnation and
in the formation Tamaulipas Superior (1) and Tamán (1) with poor to regular oil impregnation.,
oil impregnation was observed in the cuttings from fracture plains in the Tamabra and
Tamaulipas Inferior formations.
Three production test were conducted, the first one in the 2950-3000 m and 2935-2945 m
intervals in the Tamán formation, they were treated with acid and nitrogen, performed a
survey and resulted in oil, gas and little water (8.6%); the interval was plugged; the second
production test was made in the interval 2290-2300 m from formation Tamabra, with
pneumatic pump flowing water stained with oil, the interval was plugged, finally the third
production test was in the 2209-2230 m interval from Tamabra formation, it was treated with
acid amd pneumatic pumping, flowing water with traces of oil, the interval was plugged.
Below there are some comments about the events occurring during drilling in the
Chicontepec formation rocks:
In this block, there are 54 wells; light to moderate gas shows in 22 wells were reported in the
Palma Real Inferior, Tantoyuca, Guayabal, Chicontepec Superior, Medio, Inferior and Velasco
10

Basal formations. Cores and cuttings in 19 wells showed oil impregnations in the Guayabal,
Chicontepec Superior, Medio, Inferior and Velasco Basal formations .
Some producer wells from Tertiary are: Muahuapan-6A, Centurión-3 and Blenda 1 from
Chicontepec Medio Formation.
In the Miahuapan-6A well, gas shows were observed while drilling in the Palma Real Inferior
and Tantoyuca formations, lowering the mud density from 1.8 to 1.0 gr/cc and from 1.26 to
1.16 gr/cc. Light oil impregnation in cores and cuttings were observed in the Chicontepec
Superior and Medi formations o. One production test was conducted in the Chicontepec
Medio formation, in the interval 1445-1460 m, hydraulic fracturing was performed, with a
production of 176 bpd oil, 0% water and GOR: 100 m 3 /m 3 .
In the Blenda-1 well, no gas shows were observed while drilling in the Tertiary. Light and
heavy oil impregnations were observed in the Chicontepec Superior (Gilsonite tracks), Medio
and Inferior formations.
One production test was conducted in the Chicontepec Medio formation, in the interval 1645-
1660 m, hydraulic fracturing was performed, with a production of 31 bpd oil, 0% water and
GOR: 100 m 3 /m 3 .
Centurion-3 Well, gas shows were observed while drilling the Chicontepec Medio and Velazco
Basal formations, lowering the mud density from 1.34 to 1.08 gr/cc. Light oil impregnation in
cores and cuttings in Aragón and Chicontepec Medio formations. One production test was
conducted in the Chicontepec Medio formation, in the interval 1543-1583 m, hydraulic
fracturing was performed, whit a production of 6 bpd oil, 0% water and GOR: 80 m 3 /m 3 .
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Structural correlation sections were produced with geophysical logs, and the distinctive
seismic events for the Mesozoic formations were correlated with the seismic information.
The figure shown below is a correlation section with a NW to SE orientation, notice the
structural correlation between the Zapotalillo-1, Independencia-3, Zapotalillo-12, Zapotalillo-
18, Tejada-14, Tejada-61 and Huizotate-10, notice the good development of the producing
sands of the Chicontepec formation. The well Independencia-3 reached the Upper Jurassic
formations, where the hydrocarbon source rocks are, and which are currently considered
as unconventional reservoirs, also known as oil shale.
Terciar
io
Zapotalillo-1 Independencia-3 Zapotalillo-12 Zapotalillo-18 Tejada-14 Tejada-61 Huizotate-10
NW
Cretácico
Jurásico
SE
Sección II
NW structural cross section with well logs. Notice the presence of Jurassic rocks in the
subsurface of the studied area
SE
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The following figure shows the same section with seismic information, the thickness from
Mesozoic can be observed, and evidencing the developed Upper Jurassic formations.
ZAPOT-1 INDEP-3 ZAPOT-18
BLOQUE MIHUAPAM
SECCION II
ZAPOTALILLO-18
ZAPOTALILLO-12
ZAPOTALILLO-1
TEJADA-61
TEJADA-14
INDEPENDENCIA-3
HUIZOTATE-10
Seismic cross section correlation between the Zapotalillo-1, Independencia-3 and
Zapotalillo-18 wells, the presence of Jurassic source rocks can be observed.
The Miahuapan block is located in the center west side of the Chicontepec paleochannel,
The 3D seismic data available covers 100% of the area, contained in the seismic cube from
Miquetla-Miahuapan and Furbero, processed on Abril 2012 and the seismic cube Cohuca
located in the south side of the block. According to the seismic files, the tree cubes feature
migration pre-stacking time migration, with good quality and optimal vertical resolution.
In addition, 88km of bidimensional (2D) seismic data is available, segments of 56 seismic
lines inside the Miahuapan block.
N
13

The Miahuapan block features 100% of 3D seismic information with the Miquetla,
Miahuapan, Cohuca and Furbero prospects.
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History of Exploration and Development
The discovery of the fields belongs to the Miahuapan block, in the year of 1948, upon
drilling of the well Miahuapan-5, in 1957 the well Zapotalillo-2 was drilled, with
commercial oil production at an initial rate of 1,849 bpd, with 0% water and 186 m 3 /m 3 of
GOR from Tamaulipas Inferior-Pimienta formation; then in August 1961, well Zapotalillo-3
was completed with a rate of 157 bpd, 0% water and GOR 88 m 3 /m 3 from Tamabra
formation.
The maximum production rate reached was 1,080 bpd oil in June, 1976 from Tamabra
formation; now (30-06-2012) production is 348 bpd oil.
The saturation pressure is 156 Kg/cm 2 (data from PVT of Esfena-1 well, close to the area)
and the reservoir pressure is between 78 and 150 Kg/cm 2 (2,200 mv).
In 2010, operation and maintenance operations were resumed, reactivating wells with
minor repairs in the Coyotes and Horcones fields, which are on the East of this Block; it is
worth mentioning that the average rates prior to reactivation (April 2010) of wells was 20
bpd, of 79 wells in operation, with a monthly average of 1750 bpd and currently (July
2012) the average rate is 30 bpd with 110 wells in operation and an average monthly
production of 3300 bpd.
Drilling activities resumed in 2011 and 2012; three horizontal wells were drilled, and to
this day, two have been completed: Coyotes 423D and Coyotes 276D, both completed
with multifraccing (five) and the initial rate for the former was 400 bpd net oil @ 37 °API
and 0.471 mmmpcd with 30% water cut, which dropped to 15%; the initial rate for the
latter was 318 bpd of oil @ 28° API and 0.093 mmmpcd of gas and and 35% water cut; it is
still undergoing cleaning operations, hence the water cut is expected to drop as in the first
well.
15

Structural seismic section for Coyotes 423D well with horizontal trajectory.
Coyotes 423 wellbore schematic and geophysical log with the surveyed interval in which
five fractures were performed.
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Geométricos
RESU RE
Geométrico Geométric
Longitud Total
Longitud tota to
Xf
Altura (H)
Xf Xf
Altura (H) (H
Network
Network
Dirección
Dirección
Arena Otaw Ota
20/40
Arena Ottawa 20/40
Fluido Fractu Frac
Fluido de Fractura

Integrated Contract
Currently, Petróleos Mexicanos has initiated an exploration campaign for the assessment
of geological formations considered to be source rocks, i.e., shale oil, by means of
horizontal wells drilling; the drilling of one exploration well 6.3 km North of this block is
under consideration, its main objective being the Upper Jurassic's Pimienta formation.
0
500
1000
1500
2000
2500
3000
3500
NW
KS Mendez
KS SF
KS ANva
KM Tam Sup
KI Tam Inf
JS Tithoniano
JS Kimmeridgiano
Configuración
estructural cima Fm.
Pimienta (m)
Exploration location for the assessment of the Pimienta formation from Upper Jurassic
SE
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Production by Field and Reserves
The commercial exploitation of oil in this block commenced in 1976 and the production is
associated to field Tejada, which produces from Tamabra formation.
Gastos de aceite, agua (b/d)
1,200
1,000
800
600
400
200
0
01/76
11/76
09/77
07/78
05/79
03/80
01/81
11/81
09/82
07/83
05/84
03/85
01/86
11/86
09/87
07/88
05/89
03/90
01/91
11/91
09/92
07/93
05/94
03/95
01/96
11/96
09/97
07/98
05/99
03/00
01/01
11/01
09/02
07/03
05/04
03/05
01/06
11/06
09/07
07/08
05/09
03/10
01/11
11/11
Production history for Miahuapan block
The original oil in place for the the Miahuapan block is 747.573 MMbls oil and 297.656
MMMpc of gas; with a recovery factor of 13.56 % for oil and 54.69 % for gas, original oil in
place is 101.392 MMbls oil and 295.529 MMMpc gas. The accumulative production is
42.256Mbls oil and 5.72MMpc gas, for remaining reserves of 2P are estimated in 101.35
MMbls of oil and 295.524MMMpc of gas.
Área
desarrollada
por campo
(Km 2 )
Aceite
(MMbl)
Volumen
original
Gas
(MMMpc)
Aceite (Bd) Agua (Bd) Gas (mpc/d)
Aceite
(%)
Factores de
recuperación
Original oil in place, production and remaining reserves for Miahuapan block
Gas
(%)
Aceite
(Mbl)
Producción
acumulada
Gas
(MMpc)
1,400
1,200
1,000
800
600
400
200
Reservas
remanentes 2P
Aceite
(MMbl)
0
Gas
(MMMpc)
128 747.573 297.656 13.56 54.69 42.256 5.72 101.35 295.524
Gastos de gas (mpc/d)
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Infrastructure and Hydrocarbons Handling
Infrastructure of block Miahuapan
Integrated Contract
The Miahuapan block has a current (30-06-2012) gross production of 618 bpd, which are
transported by tanker trucks to the Tejada Separation Battery (BS).
Current production handling in Miahuapan block
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The Miahuapan block has the following pipelines:
Origen Destino
Roads within the Miahuapan block
Diám
(pg)
Líneas de Descarga
Long
(km)
Tubería
Año de
Construcció
n
Estado
TEJADA 1 BS TEJADA 4 0.05 LDD S/I Operativa
TEJADA 2 BS TEJADA 4 0.3 LDD S/I Operativa
TEJADA 3 BS TEJADA 4 0.3 LDD S/I Operativa
TEJADA-4 BS TEJADA 4 0.8 LDD S/I Operativa
TEJADA-6 BS TEJADA 4 0.8 LDD S/I Operativa
TEJADA-11 BS TEJADA 4 0.7 LDD S/I Operativa
TEJADA-12 BS TEJADA 4 0.7 LDD S/I Operativa
TEJADA-22 BS TEJADA 4 0.3 LDD S/I Operativa
TEJADA-24 BS TEJADA 4 0.3 LDD S/I Operativa
TEJADA-23 BS TEJADA 4 0.5 LDD S/I Operativa
TEJADA-31 BS TEJADA 4 0.9 LDD S/I Operativa
TEJADA-43 BS TEJADA 4 0.5 LDD S/I Operativa
TEJADA-52 BS TEJADA 4 1.5 LDD S/I Operativa
TEJADA-63 BS TEJADA 4 1.3 LDD S/I Operativa
Road map (roads and unpaved roads) villages, well pads and oil facilities
20

Drilling History
Drill parameters
Deep: 2,200 meters developed
Deviations: 0° (verticals) and directional in Tejada
Densidad de lodos
First stage: 1.20 gr/cm³, water base mud
Second stage: 1.30 gr/cm³, bentonite mud
Third stage: 1.45 gr/cm³; inverse emulsion mud
Objective: Tamabra
Integrated Contract
Difficulties during drilling
Surface stage
Hydration of clays, circulation losses, drag during lowering of casings, borehole instability
and shallow Gas and/or Water flows.
Intermediate stage.
Reactive shale interbeddings, pipes getting stuck and possible fluid loss, high penetration
speeds, possible increases in equivalent circulating density (DEC, in Spanish) due to
concentration of cuttings in the annulus and increases in the number of jammings and
circulation losses.
Production stage
Packing, resistance and drag, presence of formation gas, circulation losses, jammings due
to differential pressure, bit balling, accumulation of slag in the curved section.
Drill practices
The objective of this section is to review common drilling practices used in the
development of this reservoir; they are listed as a reference and not as a proposed
application of methodology and technology by AIATG.
Most of the fixes for the casing pipe (TR) in this area correspond to a design with a 9 5/8”
conductor casing, which is intended for the installation of surface tie-ins and is cemented
down to around 200 and 400 m. The production TR is 6 5/8” it is cemented at 2,200 and
2,300m.
21

he first stages are at normal pressure, and are drilled with water-based mud and with
control densities ranging between 1.20 a 1.45 gr/cm³; in the case of abnormal densities,
this is due to the shale stability control and not because it is required by the pressure
gradient. The exploitation stage is drilled with water-based fluid (sodium brine), capable
of increasing its viscosity in case of any contingency; it is also friendly to the production
formation, and the control density can be adjusted.
The Christmas tree dimensions are 9 5/8” x 6 5/8” x 2 7/8” 5,000 lb/pg²; no problems
were encountered during the drilling process.
22

***
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