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Integrated Contract <strong>EP</strong>: Pitepec<br />

Index<br />

Introduction. .............................................................................................................................3<br />

Basin description......................................................................................................................5<br />

Main Features...........................................................................................................................9<br />

Exploration and Development History.............................................................................15<br />

Production by field and reserves ......................................................................................18<br />

Infrastructure and Hydrocarbons handling....................................................................20<br />

Drilling history ..........................................................................................................................22


Introduction<br />

Integrated Contract <strong>EP</strong>: Pitepec<br />

The integrated contract area Pitepec is located in the northeast part of the “Activo<br />

Integral Aceite Terciario del Golfo” surface, covering an area of 230 Km 2 ; it is 76 Km NNW<br />

of Poza Rica, Veracruz.<br />

Location of Pitepec Contract Area<br />

Geologically, it is located in the south -­‐ center of the Tampico -­‐ Misantla basin. The main<br />

field in this area is Aragón; it was discovered in 1943; gas and oil shows were observed<br />

during drilling of Aragón-­‐2 well, which was deemed a dry non-­‐producer, hence it was<br />

plugged.<br />

On this integrated area 22 wells have been drilled, 11 are shut-­‐in, 6 are plugged and 5 are<br />

in operation. Maximum production was 150 bpd of oil with 6 active well in February 2012;<br />

currently the (30/06/12) production is 61 bpd oil, its cumulative production is 822.807 Mbl<br />

oil and 583.005 MMpc gas. The oil type is light crude, with a density ranging between 32<br />

to 40° API; the bottomhole pressure measured recently in the Aragón-­‐191 well (June<br />

2012) was 73.8 Kg/cm 2 at a depth of 1,040 m.. The current production system in the<br />

area is rod pumping. The average depth of the tertiary reservoirs is 1,050 m.


Integrated Contract <strong>EP</strong>: Amatitlán<br />

During drilling of the exploration wells in the Tamaulipas Superior, Tamaulipas Inferior,<br />

Pimienta and Tamán Mesozoic formations, gas shows were observed; oil impregnation<br />

was observed in the channel samples and cores.<br />

The following information was obtained from PVT analyses of various wells from the<br />

above formation in the Chicontepec Paleochannel area:<br />

• Chicontepec-­‐2A Well (located 5.0 Km southwest of area).<br />

Tamaulipas Superior Formation: 37.3 °API Oil, gas solubility at initial pressure relationship<br />

(Rsi), 168.70 m 3 /m 3 ; Oil Volume Factor (Bo), 1.5683 m 3 /m 3 ; and saturation pressure (Pb),<br />

206.70 Kg/cm 2 .<br />

• Presidente Miguel Alemán-­‐772 Well (located 85 Km southeast of area).<br />

Tamaulipas Inferior Formation: 35.7 °API Oil; gas solubility at initial pressure relationship<br />

(Rsi), 179.50 m 3 /m 3 ; Oil Volume Factor (Bo), 1.6270 m 3 /m 3 ; a saturation pressure (Pb),<br />

215.20 Kg/cm 2 .<br />

• Caviar-­‐1 Well (located 123 Km northeast of area).<br />

Pimienta Formation: 15.74 °API Oil; gas solubility at initial pressure relationship (Rsi),<br />

33.28 m 3 /m 3 ; Oil Volume Factor (Bo), 1.1659 m 3 /m 3 ; saturation pressure (Pb), 106.16<br />

Kg/cm 2 .<br />

• Furbero-­‐106 Well (located 73 Km southeast of area).<br />

Tamán Formation: 37.11 °API Oil; gas solubility at initial pressure relationship (Rsi), 179.60<br />

m 3 /m 3 ; Oil Volume Factor (Bo), 1.8138 m 3 /m 3 ; saturation pressure (Pb), 175.10 Kg/cm 2 .


Basin Description<br />

Integrated <strong>EP</strong>:<br />

The Tampico -­‐ Misantla basin is located in eastern Mexico and it spans from southern<br />

Tamaulipas to the central part of the state of Veracruz, along with a small part of the east<br />

side of the states of San Luis Potosí, Hidalgo and north of Puebla, down to the 200-­‐m<br />

isobaths of the Gulf of Mexico's continental shelf.<br />

Location of Tampico – Misantla Basin.<br />

The crystalline basement is formed by igneous and metamorphic rock, their ages ranging<br />

from Permian to the middle Jurassic. In the sedimentary column of the Tampico-­‐Misantla<br />

province, the following tectono-­‐sequences are identified:<br />

First tectono-­‐sequence (Synrift). Started in the Triassic (250My), with the deposition of<br />

continental clasts from alluvial and fluvial environment with some lava flowed from the<br />

5


Integrated <strong>EP</strong>:<br />

Huizachal formation, from the late Triassic age (Noriense-­‐Retiense), over crystalline and<br />

metamorphic basements, later the Huayacocotla formation from the Lower Jurassic<br />

(Hettangiano-­‐Pliensbachiano) was deposited, and it is a sandstones and shale sequence,<br />

from transgressive oceans. By the middle Jurassic, continental conditions were restored,<br />

with Clasts from the Cahuasas formation being deposited, by the end of this period, a new<br />

marine transgression commenced, and favored the deposition of oolithic limestone for<br />

the Huehuetepec formation (Bathonian), and sandy limestone with bioclasts and ooliths<br />

for the Tepexic formation (Callovian), which were overlain by calcareous and<br />

carbonaceous shale with plenty of organic matter, from the Santiago formation<br />

(Oxfordian), deposited on constrained, low-­‐energy seas; as the marine transgression<br />

moved forward, carbonate ramps developed around the basement highs -­‐ inside and on<br />

the edge of the former, sandy-­‐clayey limestone and oolithic limestone from the San Pedro<br />

and San Andrés formations were deposited, (Kimmeridgian), respectively, and their lateral<br />

equivalents toward deeper waters, namely, the clayey limestones with scarce bioclasts<br />

and oolites (Chipoco formation) and basin black clayey limestones (Tamán formation).<br />

The transgressive sea conditions continued so that during the Tithonian-­‐Portlandian, a<br />

maximum flooding surface would occur, with most of the basement highs being left in<br />

underwater conditions. During that time, clayey-­‐carbonaceous limestones were<br />

deposited, (rich in organic matter) from the Pimienta formation, from a relatively-­‐deep-­‐<br />

water environment, which is present throughout the region and only in the parts<br />

emerging from the basement, which were under coastal and/or shoreline conditions; La<br />

Casita formation was deposited, which is constituted by glauconitic sandstones.<br />

Passive Margin Tectono-­‐sequence. The marine transgression carried on and ultimately<br />

flooded all of the basement highs, it deposited on the internal parts, limestones and<br />

dolomites, while on the edges, the organic-­‐reefal growths development commenced. At<br />

the same time, and due to the thermal subsidence, the lower areas deepened, giving rise<br />

to deep sea basins, where the three members of the Tamaulipas Inferior formation were<br />

deposited (calcarenithic member, bentonitic member and creamy limestone member)<br />

corresponding to the Berriasian-­‐Barremian age. During the Aptian stage, the Otates<br />

horizon formation deposition occurred, which is considered to be a condensed sequence.<br />

During the Albian, along the entire Tuxpan platform a reef edge, roughly 1400 m thick,<br />

which gave rise to lagoon facies on the inside of the platform, whereas for the reef front,<br />

the Tamabra formation, featuring proximal, mean and distal slope facies, developed due<br />

to the reefal denudation, and changes facies with the chalky limestone Tamaulipas<br />

Superior formation.<br />

6


Integrated <strong>EP</strong>:<br />

By the end of the Cenomanian, the platform remained under subaerial conditions by a<br />

regressive marine pulse, which was followed by a new transgressive event allowing the<br />

deposition both in lagoon facies and in the mean, distal slope and basin of the Turonian<br />

Agua Nueva (black clayey limestones with black shales interbeddings), Coniacian-­‐<br />

Santonian San Felipe (greenish-­‐grey clayey limestone with abundant olive green bentonite<br />

interbeddings) and Campanian-­‐Maastrichtian Méndez (clayey limestones and green/red<br />

marls) formations; the period of this tectono-­‐sequence ended with the deposition of the<br />

last formation.<br />

Eventos<br />

Tectónicos<br />

Ambientes<br />

sedimentarios<br />

Geologic column for the Tampico-­‐Misantla basin with reservoir rock, source rock<br />

(unconventional reservoirs), tectonic events and sedimentary environments.<br />

The foreland basin tectono-­‐sequence is characterized by the onset of the Sierra Madre<br />

Oriental's (SMO) uplift, which gave rise to a greater contribution of terrigenous material<br />

7


Integrated <strong>EP</strong>:<br />

sediments; these marine Cenozoic depositions were originally defined as Tampico-­‐<br />

Misantla Basin by López-­‐Ramos (1956).<br />

The ongoing uplift of the SMO left very narrow coastal plains and continental shelves,<br />

hence the coastal systems would go from a prodelta to a slope, and where the transport<br />

of sediments by means of turbidity currents prevailed, there would be flow of debris and<br />

landslides, which would produce deposition of submarine fans at the bottom of the<br />

seafloor (basin), overlapping each other and generating submarine erosion during their<br />

development.<br />

By the end of the Cenozoic, deltaic environments prevailed.<br />

Tuxpan<br />

Poza Rica<br />

Tecolutla<br />

Tertiary Sedimentary model (Paleogene and Neogene). Note that delta environments<br />

were deposited above the Chicontepec formation<br />

8


Main Features<br />

Integrated Contract <strong>EP</strong>: Amatitlán<br />

The main producing formation is the Chicontepec formation, having evidence of<br />

production in the Pimienta formation (Upper Jurassic).<br />

The reservoirs in this Contract Area are located in combined, structural (anticlines with<br />

subtle dips with four-­‐direction closure) and stratigraphic traps.<br />

This Contract Area features the Aragón-­‐2, Aragon-­‐1001, Pedregosa-­‐1 and Tlacolula-­‐10<br />

exploration wells; slight oil impregnations were evidenced in the cutting samples;<br />

attractive gas shows were found in the Agua Nueva, Tamabra, Tamaulipas Superior<br />

and Tamán formations.<br />

In the Aragón-­‐2 well, slight oil shows were observed in the Agua Nueva formation, one<br />

core without oil impregnations was taken, no production tests were performed and the<br />

Cretaceous channel samples did not exhibit oil impregnations.<br />

In the Aragón-­‐1001 well, slight oil and gas shows were observed in the Tamaulipas<br />

Superior and Pimienta formations, nine cores without oil impregnations was taken, no<br />

production tests were performed and the Cretaceous cutting samples exhibited slight oil<br />

impregnations from San Felipe and Tamaulipas Superior formations.<br />

In the Pedregosa-­‐1 well, high gas readings were registered at the Taman formation; no<br />

production tests were performed; two cores were cut from the Agua Nueva formation<br />

with poor oil impregnation on the fracture planes; the channel samples exhibited a slight<br />

oil impregnation from the Agua Nueva and Tamaulipas Superior formations.<br />

In the Tlacolula-­‐10 well, gas shows were observed during the drilling, little oil and sal<br />

water in the Agua Nueva formation and strong gas and oil shows in the Tamaulipas<br />

Superior formation. In the #20 core (2300 -­‐ 2306.3 m) in the Tamaulipas Superior<br />

formation, traces of oil and a strong smell of gas were detected; no impregnations in<br />

channel samples were reported.


Integrated <strong>EP</strong>:<br />

Two formation tests were conducted in the Tamaulipas Superior formation, 50 meters of<br />

oil with plenty of gas and 75 meters of gasified mud were recovered from the production<br />

tubing (TP, in Spanish).<br />

Below are some comments on the events which occurred during drilling in the<br />

Chicontepec formation rocks:<br />

In the Galo-­‐1 well, gas shows were observed in the low magnitude mud and in the regular<br />

magnitude channel samples during the drilling. Cores were cut from the Chicontepec<br />

Medio formation (8), showing light oil impregnation. The channel samples exhibited poor<br />

oil impregnation in the Aragón, Chicontepec Medio and Basal formations.<br />

A production test was performed in Chicontepec Medio, resulting in a production of 13<br />

bpd oil, 0% water and a GOR of 100m 3 /m 3 .<br />

In the Aragón-­‐134 well, no gas shows were detected while drilling. Four cores were cut in<br />

the Chicontepec formation, with slight oil impregnation and residual organic matter<br />

(gilsonite). The channel samples from the Chicontepec Medio and Inferior formation had<br />

light oil impregnation stains.<br />

Four production tests with hydraulic fracturing were performed in the Chicontepec Canal<br />

formation, the first two tests produced 100% water; in the third test, the 815-­‐860 m<br />

interval produced 14 bpd oil, 71% water and GOR 180m 3 /m 3 ; finally the fourth test in the<br />

815-­‐860 m, 874-­‐885 m and 1100-­‐1105 m intervals produced 14 bpd oil, 71% water and<br />

180m 3 /m 3 GOR.<br />

In the Tlacolula-­‐446 well, no gas shows were observed while drilling. Three cores were cut,<br />

exhibiting light yellow oil impregnations. The channel samples from Chicontepec Medio<br />

and Chicontepec Inferior formation showed light oil.<br />

Four production tests were conducted in the Chicontepec Canal formation with hydraulic<br />

fracturing, two of them with production: one in the 1470-­‐1490 m interval, with a<br />

production of 7 bpd oil, 22% water and GOR 125m 3 /m 3 and the other test in the 811-­‐825<br />

m interval with a production of 5 bpd oil, 92% water and GOR 186m 3 /m 3 .<br />

In the Aragón-­‐2 well, light gas and oil shows were observed during drilling through the<br />

Chicontepec Medio formation. The channel samples from the Chicontepec Superior<br />

formation showed light oil impregnation.<br />

10


No production tests were conducted.<br />

Integrated <strong>EP</strong>:<br />

In the Aragón-­‐78 well, no gas shows were observed during drilling. No cores were cut in<br />

the Tertiary formation and the channel samples did not exhibit any impregnation.<br />

Two production tests with hydraulic fracturing were conducted in the Chicontepec Medio<br />

formation; in the first test a treatment fluid volume of 342 m 3 was recovered, with 7 m 3<br />

remaining in the well; this interval was deemed an un-­‐economic producer and the second<br />

test yield an estimated production of 31 bpd oil.<br />

In the Ayacaxtla-­‐1 well, no gas shows were observed while drilling. 26 cores were cut, 20<br />

in the Chicontepec Medio formation and 6 in Chicontepec Superior, with poor light and<br />

residual oil impregnation, respectively. The channel samples had poor light oil and asphalt<br />

impregnation in the Chicontepec Superior, Medio e Inferior formation.<br />

Three production tests with hydraulic fracturing were performed, the first in the<br />

Chicontepec Inferior formation at the 1295-­‐1305 m and 1315-­‐1330 m intervals, the drilling<br />

flowed 80% salt water; this interval was deemed non-­‐producing, the second test was<br />

performed in the Chicontepec Medio formation, 1020-­‐1040 m and 1050-­‐1070 m intervals,<br />

the drilling recovered oil stained water and little gas -­‐ this interval was deemed invaded by<br />

salt water and the third test was performed in the Chicontepec Medio formation, 945-­‐955<br />

m interval, flowing 6 bpd oil, 0% water and GOR 10 m 3 /m 3 .<br />

11


Integrated <strong>EP</strong>:<br />

The well geophysical logs were used to produce structural correlation sections, and the<br />

distinctive seismic events of the Mesozoic formations were correlated to the seismic<br />

information. The figure below is a correlation section with a W-­‐E orientation; the<br />

structural correlation among the Camaitlan-­‐2, Pitepec-­‐1, Aragón-­‐1, Aragón-­‐1001 &<br />

Coyotes-­‐3 can be observed; notice the fine development of the Chicontepec formation's<br />

producing sands. The Camaitlán-­‐2, Aragón-­‐1001 & Coyotes-­‐3 wells reached the Upper<br />

Jurassic formations, where the hydrocarbon source rocks are -­‐ these are currently<br />

considered to be unconventional reservoirs, or Oil Shale.<br />

Structural cross section with well logs. Notice the presence of Jurassic rocks in the<br />

subsurface of the studied area.<br />

12


Integrated <strong>EP</strong>:<br />

The following figure shows a section with seismic information, which shows the Mesozoic<br />

rock thicknesses, and evidencing the development of the Upper Jurassic formations.<br />

PIT<strong>EP</strong>EC-­‐1 ARAGÓN-­‐1 ARAGÓN-­‐1001 COYOTES-­‐3<br />

W-­‐E Seismic section between the Pitepec-­‐1, Aragón-­‐1, Aragón-­‐1001 & Coyotes-­‐3 wells, it<br />

shows the presence of Jurassic source rocks.<br />

The Pitepec contract area is located on the north side of the Chicontepec Paleochannel;<br />

88.6% of this area has 3D seismic information from the Amatitlán prospect, which was<br />

processed on April 2009. According to current seismic files, this seismic cube has pre-­‐<br />

stacking time migration (PSTM) with good quality and vertical resolution.<br />

There are also 166.5 km of bidimensional seismic (2D), segments comprising 19 seismic<br />

lines inside the Pitepec contract area.<br />

13


Integrated <strong>EP</strong>:<br />

The Pitepec contract area features a 88.6% coverage of 3D seismic data from the<br />

Amatitlán prospect<br />

14


Exploration and Development History<br />

Integrated Contract <strong>EP</strong>: Amatitlán<br />

The Pitepec contract area was discovered in 1943 upon drilling the Aragón-­‐1 and Aragón-­‐2<br />

wells; there is only drilling information available on the first well, stating that it reached a<br />

depth of 1,609 mvd; the second well exhibited gas and oil shows, both wells were<br />

abandoned as dry non-­‐producers. The first producing well on this area was Aragón-­‐501,<br />

completed in 1974, with a rate of 94 bpd with 0 % water in the Chicontepec Medio<br />

formation; in 1947 the Tlacolula-­‐10 well recovered 50 meters of oil and a lot of gas from<br />

Tamaulipas Superior formation..<br />

In February 2012 the area reached its maximum production: 150 bpd with six wells in<br />

operation.<br />

In 2010, operation and maintenance were resumed through minor workovers conducted<br />

in the Coyotes and Horcones fields, these fields are located to the East of this contract<br />

area; the average rates prior to reactivation (April 2010) of the wells were 20 bpd, with 79<br />

wells in operation, with a 1750 bpd monthly average; currently (July 2012), the average<br />

rate is 30 bpd with 110 wells in operation and an average monthly production of 3300<br />

bpd.<br />

Drilling activity resumed in 2011 and 2012, three horizontal wells were drilled and to this<br />

date two more wells have been finished: Coyotes 423D and Coyotes 276D, both were<br />

finished with multifraccing (five); the initial rate for the first well was 400 bpd net oil, 37<br />

ºAPI and 0.471 mmmpcd with 30% water cut which dropped to 15%; the initial rate for the<br />

second well was 318 bpd oil, 28 ºAPI and 0.093 mmmpcd gas and 35% water cut -­‐ the well<br />

still undergoing swabbing, therefore the water cut is expected to drop as observed in the<br />

first well.


Integrated <strong>EP</strong>:<br />

Seismic structural section for Coyotes 423D well with horizontal trajectory.<br />

Coyotes 423D Wellbore Schematics and geophysical log with the surveyed interval in<br />

which five fractures were performed.<br />

16<br />

RESU RE<br />

Geométrico Geométric<br />

Longitud tota to<br />

Xf Xf<br />

Altura (H) (H<br />

Network<br />

Dirección<br />

Arena Otaw Ota<br />

20/40<br />

Fluido Fractu Frac


Integrated Contract <strong>EP</strong>: Amatitlán<br />

Currently, Petróleos Mexicanos has initiated an exploration campaign for the assessment<br />

of geological formations considered to be source rocks, i.e., shale oil, by means of<br />

horizontal wells drilling; the drilling of one exploration well 1.4 km from this contract area<br />

is under consideration, its main objective being the Upper Jurassic's Pimienta formation.<br />

0<br />

500<br />

1000<br />

1500<br />

2000<br />

2500<br />

3000<br />

3500<br />

NW<br />

KS Mendez<br />

KS SF<br />

KS ANva<br />

KM Tam Sup<br />

KI Tam Inf<br />

JS Tithoniano<br />

JS Kimmeridgiano<br />

Configuración<br />

estructural cima Fm.<br />

Pimienta (m)<br />

Exploration location for the assessment of the Pimienta formation from Upper Jurassic<br />

SE


Integrated <strong>EP</strong>:<br />

Production by Field and Reserves<br />

The commercial exploitation of oil in this contract area commenced in 1974 and the<br />

production is associated to the reservoirs in the Aragón, Pastoria and Tlacolula fields.<br />

The saturation pressure is 65 Kg/cm 2 and the current pressure is 77 Kg/cm 2 .<br />

Gasto de aceite y agua (bpd)<br />

400<br />

380<br />

360<br />

340<br />

320<br />

300<br />

280<br />

260<br />

240<br />

220<br />

200<br />

180<br />

160<br />

140<br />

120<br />

100<br />

80<br />

60<br />

40<br />

20<br />

0<br />

01/08/1974<br />

14/12/1975<br />

27/04/1977<br />

09/09/1978<br />

22/01/1980<br />

05/06/1981<br />

18/10/1982<br />

01/03/1984<br />

14/07/1985<br />

26/11/1986<br />

09/04/1988<br />

22/08/1989<br />

04/01/1991<br />

18/05/1992<br />

30/09/1993<br />

Suma de Aceite (bpd) Suma de Agua (Bd) Suma de Gas (mpc/d)<br />

Production history for Pitepec contract area<br />

12/02/1995<br />

26/06/1996<br />

08/11/1997<br />

23/03/1999<br />

04/08/2000<br />

17/12/2001<br />

01/05/2003<br />

12/09/2004<br />

25/01/2006<br />

09/06/2007<br />

21/10/2008<br />

05/03/2010<br />

18/07/2011<br />

2000<br />

1800<br />

1600<br />

1400<br />

1200<br />

1000<br />

800<br />

600<br />

400<br />

200<br />

0<br />

Gasto de gas (mpc/d)<br />

18


Integrated <strong>EP</strong>:<br />

The original oil in place for the Pitepec contract area is 6,325.271 MMbls oil and 2,435.364<br />

MMMpc gas; with a recovery factor of 10.09 % for oil and 69.73 % for gas. The cumulative<br />

production is 822.807 Mbls of oil and 583.005 MMpc of gas, for 2P estimated remaining<br />

reserves of 233.306 MMbls of oil and 686.871 MMMpc of gas.<br />

Chicontepec<br />

Cumulative Production<br />

up to June 30th, 2012<br />

Chicontepec<br />

OOIP<br />

Reserves up to<br />

January 1st, 2012<br />

Mesozoic<br />

PIT<strong>EP</strong>EC<br />

Cumulative Production<br />

Oil (Mbbl) Gas (MMpc) BOE(Mbpce)<br />

822.8070 583.0050 1409.9544<br />

Reserves<br />

Oil (MMbbl) Gas (MMMpc) BOE(MMbpce)<br />

6325.2707 2435.3644 6913.1893<br />

1P 7.90568 11.87736 10.7730<br />

2P 233.30589 686.87094 399.1226<br />

3P 637.64291 1697.72976 1047.4899<br />

Prospective Resources<br />

Oil (MMbbl) Gas (MMMpc) BOE(Mmbpce)<br />

151 418 251.9089<br />

Original volume, production and remaining reserves for the Pitepec contract area<br />

19


Infrastructure and Hydrocarbons handling<br />

Infrastructure contractual area Pitepec<br />

Integrated Contract <strong>EP</strong>: Amatitlán<br />

The contractual area Pitepec has a gross production of 9 bpd, which is transported by<br />

means of tanker trucks to the Soledad Norte Separation Battery (BS).<br />

Proposal for production handling for the Pitepec contract area<br />

This contract area is not fitted with pipeline:<br />

Source Destination Diameter (in) Lenght (Km)<br />

NO PIPES


Roads within the Pitepec contract area<br />

Integrated <strong>EP</strong>:<br />

Road map (roads and unpaved roads) villages, well pads and oil facilities<br />

21


Drilling History<br />

Drilling parameters<br />

Depth: 1,700 meters developed<br />

Deviations: Verticals and Deviated<br />

Mud density<br />

First stage: 1.05-­‐1.15 gr/cm³; inhibited water-­‐based<br />

Second stage: 1.15-­‐1.20 gr/cm³; inhibited water-­‐based<br />

Third stage: 1.20-­‐1.28 gr/cm³; inverse emulsion<br />

Objective: Chicontepec<br />

Difficulties during drilling<br />

Integrated Contract <strong>EP</strong>: Amatitlán<br />

Surface stage<br />

Hydration of clays, circulation losses, drag during lowering of casings, borehole instability<br />

and shallow Gas and/or Water flows.<br />

Intermediate stage.<br />

Reactive shale interbeddings, pipes getting stuck and possible fluid loss, high penetration<br />

speeds, possible increases in equivalent circulating density (DEC, in Spanish) due to<br />

concentration of cuttings in the annulus and increases in the number of jamming and<br />

circulation losses.<br />

Production stage<br />

Packing, resistance and drag, presence of formation gas, circulation losses, jamming due<br />

to differential pressure, bit balling, accumulation of slag in the curved section.<br />

Drilling practices<br />

Most of the casing piping (TR, in Spanish) setups in this area comprise a 13 3/8" and 10<br />

3/4" conductor casing, which is intended for the installation of surface tie-­‐ins and is<br />

cemented down to around 100 to 150 m. The 9 5/8" and 7 5/8" intermediate casing is<br />

cemented at average depths between 300 and 500 m, the setting depth for that stage is<br />

proposed based on the correlation wells. Finally, the third stage is drilled and fitted with a<br />

7" and 5 1/2" casing which is cemented down to the total depth.


Integrated <strong>EP</strong>:<br />

The first stages are at normal pressure, and are drilled with water-­‐based mud and with<br />

inverse emulsion mud with control densities ranging between 1.25 to 1.30 gr/cm3; in the<br />

case of abnormal densities, this is due to the shale stability control and not because it is<br />

required by the pressure gradient. The exploitation stage is drilled with water-­‐based fluid<br />

(sodium brine), capable of increasing its viscosity in case of any contingency; it is also<br />

friendly to the production formation, and the control density can be adjusted.<br />

The Christmas tree dimensions are 13 3/8” x 9 5/8” x 7” X 2 7/8” and 10 3/4” x 7 5/8” x 5<br />

1/2” x 2 7/8” 5,000 lb/pg²; no problems were encountered during the drilling process.<br />

23


Integrated <strong>EP</strong>:<br />

WELLBORE SCHEMATIC TYPE 1: PIT<strong>EP</strong>EC<br />

TR 10 3/4, J-55, 54 Lb/pie BCN<br />

TR 7 5/8, J-55, 36 Lb/pie BCN” 402 m<br />

EMPACADOR 750 m<br />

DISPARÓ: 18-02-11<br />

FRACTURÓ:01-03-11<br />

DISPARÓ: 30-05-10<br />

FRACTURÓ:02-06-10<br />

DISPARÓ: 30-04-10<br />

FRACTURÓ:20-05-10<br />

TR5 1/2 , J-55, 36 Lb/pie BCN<br />

P.T. = 1770 m<br />

815m<br />

860m<br />

874m<br />

885m<br />

1100m<br />

1105m<br />

1770 m<br />

55 m<br />

Guayabal 4 m<br />

Aragon<br />

Chicontepec Sup<br />

Chicontepec Med<br />

Chicontepec Inf<br />

Velasco<br />

P.T.<br />

74m<br />

389m<br />

562m<br />

1110m<br />

1660m<br />

Mendez 1700m<br />

1770m<br />

24


Integrated <strong>EP</strong>:<br />

WELLBORE SCHEMATIC TYPE 2: PIT<strong>EP</strong>EC<br />

TR 13 3/8, J-55, 54 Lb/pie BCN<br />

TR 9 5/8, J-55, 36 Lb/pie BCN” 303 m<br />

EMPACADOR 750 m<br />

DISPARÓ: 13-03-11<br />

FRACTURÓ:16-03-11<br />

DISPARÓ: 16-05-10<br />

FRACTURÓ:19-05-10<br />

TR 7, J-55, 36 Lb/pie BCN<br />

P.T. = 1643 m<br />

***<br />

1163m<br />

1180m<br />

1479m<br />

1490m<br />

1640 m<br />

145 m<br />

Guayabal 4 m<br />

Chicontepec Sup<br />

Chicontepec Med<br />

Chicontepec Inf<br />

P.T.<br />

389m<br />

562m<br />

1110m<br />

Mendez 1600m<br />

1643m<br />

25

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