Santuario Block, Mature Fields South Region. Executive Summary. Block. Santuario

Santuario Block, Mature Fields South Region Executive Summary Block Santuario South Region 1

Santuario Block, Mature Fields South Region Table of Contents Page 1. General Description of the Block 3 1.1 General Description 3 1.2 General properties of the reservoirs 6 1.3 Geological Characteristics 7 1.4 Drilling Characteristics 11 1.5 Social and Environmental Conditions 12 2 Development of the Block 12 2.1 Seismic 2D and 3D 12 2.2 Wells drilled, shut in, plugged and in production 15 2.3 Drilling Results 15 2.4 Well Maintenance 17 2.5 Production History 18 2.6 Infrastructure Facilities 21 2.7 Facilities Maintenance 31 3 Block Potential 32 3.1 Hydrocarbon Reserves and Cumulative Production 32 2

Santuario Block, Mature Fields South Region 1. General Description of the Block 1.1 General Description EXECUTIVE SUMMARY The Santuario Block contains three oil fields, Santuario, El Golpe and Caracolillo. The fields belong to the Pemex Exploration and Production (PEP) investment project Golpe Puerto Ceiba and are managed by the Bellota Jujo Asset of the Southern Region (RSUR) of PEP. Geographically the block is located in the Salina del Istmo Basin, on the West side of the state of Tabasco in Southeast Mexico. It is positioned north of the morphotectonic depression, known as Istmo de Tehuantepec, and West of the city of Comalcalco, in the state of Veracruz. Figure 1 Geographic location of the fields Santuario, El Golpe and Caracolillo 3

Santuario Block, Mature Fields South Region To delineate the area of the Block the following polygons were created with their respective geographical and UTM coordinates (Table 1 and Figure 2) SURFACE POLYGON CORNER GEOGRAPHICAL COORDINATES COORDINATES UTM X Y X Y 1 93.416772 18.299987 455953 2023304 2 93.416671 18.266661 455955 2019616 3 93.450000 18.266642 452432 2019623 4 93.449990 18.233333 452424 2015938 5 93.466656 18.233336 450662 2015942 6 93.466646 18.216672 450659 2014099 7 93.533321 18.216666 443609 2014117 8 93.533334 18.300036 443634 2023341 9 93.466671 18.300007 450679 2023319 10 93.466663 18.350000 450694 2028850 11 93.399997 18.349992 457738 2028832 12 93.399991 18.300023 457727 2023304 Table 1 Geographic and UTM Coordinates of the corners of the Santuario Block polygon 4

Santuario Block, Mature Fields South Region Block Santuario, Tertiary Area (Comalcalco) Figure 2 Corners of the Surface Polygon Block Santuario, geographical coordinates 5

Santuario Block, Mature Fields South Region 1.2 General Properties of the Reservoirs The Santuario Block is made up of three fields, Santuario, El Golpe and Caracolillo. The sediments in these fields are structurally compartmentalized and separated by a system of main faults. Sand packages of different thicknesses, separated by shale layers at average depths between 2,500 to 3,600 meters are identified in the three fields.. Figure 3 Map with the location of the field of the Block Santuario PETROPHYSICAL PROPERTIES Field Field area (km2) Santuario 5.94 El Golpe 10.307 Reservoir Rock Porosity Permeability Gross Net Depth Type Type (%) (md) Thickness(m) Thickness(m) (m) Structural Sandstones Stratigraphic 18 24 30 500 877 245 2950 3600 Structural Sandstones Stratigraphic 24 70 500 760 274 3,100 6

Santuario Block, Mature Fields South Region Caracolillo 1.42 Structural Stratigraphic Sandstones 11 26 10 100 90 60 2,500 Field Density (*API) GOR (m3/m3) Table 2 Reservoir Properties Initial Pressure (kg/cm2) FLUID PROPERTIES Current Pressure (kg/cm2) u@sc (cp) Temp (*C) Boi (m3/m3) Formation H2O Salinity x 1000(pm) P.Sat (kg/cm2) Santuario 35 90 120 351 248 5.6 85 1.32 90 160 209 El Golpe 36 125 426 97 5.7 75 1.364 60 75 133 Caracolillo 29 294 50 95 135 246 Boi = Oil Formation Volume Factor at Initial Pressure, u = Viscosity, @sc = Surface conditions Table 3 Reservoir Properties The sandstone reservoirs present in Santuario, El Golpe and Caracolillo fields are from the Tertiary period. A total of fifty six (56) sand reservoirs (23, 25 and 8) are identified in the three fields respectively in the Upper Concepcion, Encanto and Filisola geologic sections. The majority of production from these three fields has been from the Upper Concepcion. The top is the Filisola formation which is one of the producing formations. 1.3 Geological Characteristics The geological type in the area of the fields is made up by the following formations: Pleistocene, Plio Pleistocene formation Paraje Solo, Pliocene formations Filisola, Upper and Lower Concepcion and Encanto. The Upper Concepcion formation stands out with ideal characteristics for hydrocarbon reservoirs. The sediments are from the Tertiary age and fifty six (56) separate sand bodies with hydrocarbon potential have been identified in the Upper Concepcion formation, which is the largest contributor to the production. These sands are separated by shale beds and are from a deltaic front system deposited as submarine fans in continental slope basins. A regional study was completed with the objective to define the geological Tertiary plays. In a broad way the study integrated geological information, geophysics, paleontology, and available production data. It 7

Santuario Block, Mature Fields South Region was processed in such a way that the results opened a new horizon and provide guidelines for a coherent exploration of the area. The architecture of the three fields consists of a system of normal faults oriented SW NE with dip to the NW with the corresponding antithetic faults dipping to the SE. The fault pattern at the regional level follows the same SW NE general orientation of the system of faults at El Golpe, Tuplico and Castarrical fields. The continuity of the fault system at Santuario, El Golpe, Tupilco and Castarrical suggests the presence of a regional mega structure, which according to its location relative to the Comalcalco fault, corresponds to a regional anticline structure, collapsed in a crest type rollover. At a regional level the Tertiary fields are located in the Comalcalco basin and are part of the SW NE structural trend containing Santuario, El Golpe, and other fields in the trend such as Tupilco and Castarrical fields. 8

Santuario Block, Mature Fields South Region Figure 4 Location of the fields in the regional tectonic context The Santuario field is managed by the Bellota Jujo administrative Asset of the Southern Region (RSUR) of PEP. It is located in NE portion of the state of Tabasco and geologically in the Comalcalco sub basin part of the tertiary basins of the SE of Mexico and is part of the structural trend of the Santuario, El Golpe, Tupilco, Castarrical and Caracolillo fields. The Block area is limited to the East by the Salina del Istmo basin and to the West by the Akal high. The Comalcalco basin was affected by compression during Middle Miocene and Early Pleistocene, known as Chiapaneco event. During the Middle Pliocene and Pleistocene there were tensile and salt tectonic events that originated the intense faulted structures. The structural stratigraphic features were defined by correlations and are made up of eleven (11) main faults that confirm the tensile fault environment that compartmentalized the Santuario field. From the hydrodynamic point of view all faults are sealing faults and act as cap rocks. Through lateral lithologic distribution and the interpretation of electrofacies it was possible to establish the environments of sedimentary deposition which are primarily made up of a NE SW channel, bordered by sand bars. All environments are part of a deltaic depositional environment. AGE FORMATION DEPTH (meters) THICKNESS (m) Pleistocene Outcrops 60 Plio Pleistocene Paraje Solo 60 104 Pliocene Filisola 164 2666 Miocene Upper Concepcion 2830 1480 Miocene Lower Concepcion 4310 170 Miocene Encanto 4480 Table 4 Stratigraphic column Santuario field The El Golpe field is also managed by the Bellota Jujo administrative Asset of the Southern Region (RSUR) of PEP. It is located in NE portion of the state of Tabasco and geologically in the Comalcalco subbasin of the Salina del Istmo basin which is part of the tertiary basins of SE Mexico. The Comalcalco subbasin is adjacent and to the North of the Mesozoic producing area of Chiapas Tabasco. The geological fault of Comalcalco, a regional fault with strike NE SW and that dips to the NW, separates the two areas. Another parallel fault to the Comalcalco fault seems to separate the Comalcalco sub basin from the 9

Santuario Block, Mature Fields South Region Salina del Istmo basin. These two large faults probably are the limits of the Comalcalco sub basin, which shows an expanded Tertiary stratigraphic section. The limestone reservoirs of the Cretaceous period that are producers in the Chiapas Tabasco area, may be present in the El Golpe but at lower depths. Geologically the field is part of the structural trend of the Santuario, El Golpe, Tupilco, Castarrical and Caracolillo fields that include broad structures with normal faulting. The field is a local homocline structure with a NE SW orientation detached by a system of normal faults with NE SW strike. Structurally the field is divided into several blocks that that contain several producing reservoirs. The most important accumulation is located in the central portion of the structure. The geological model of the El Golpe field obtained from the interpretation of 2D and 3D seismic is consistent with the geological model from wells. There is an evident relation between the producing zones of the field. AGE FORMATION DEPTH (meters) THICKNESS (m) Pleistocene Outcrops 37 Plio Pleistocene Paraje Solo 37 480 Pliocene Filisola 517 525 Miocene Upper Concepcion 1042 2246 Miocene Lower Concepcion Table 5 Stratigraphic column field El Golpe The Caracolillo field is also managed by the Bellota Jujo administrative Asset of the Southern Region (RSUR) of PEP. It is located in NE portion of the state of Tabasco and geologically in the Comalcalco subbasin. It is part of the tertiary basins of SE Mexico and is part of structural trend of the Santuario, El Golpe, Tupilco, and Castarrical fields. The structural deformations of the sediments of the Upper Tertiary were originated during the Miocene and Plio Pleistocene by the tectonic events known as Chiapaneco and Cascadiano which, together with salt tectonics, made up broad intensely faulted structures. It is part of parallel structures that regionally show up in the Comalcalco fault and where the influence of salt domes created independent block separated by faults. The local structure is homoclinal with flanks affected by faults. The trap is structural. AGE FORMATION DEPTH (meters) THICKNESS (m) Pleistocene Outcrops 37 Plio Pleistocene Paraje Solo Undetermined Pliocene Filisola 163 2313 Miocene Upper Concepcion 2476 1014 Miocene Encanto 3470 10

Santuario Block, Mature Fields South Region Table 6 Stratigraphic column field Caracolillo 1.4 Drilling Characteristics Recently wells were drilled in the El Golpe field. Drilling is normally done in three (3) stages using casing of 20, 13 3/8, 9 5/8, and 7. Completions are done using 2 3/8 and 2 7/8 production tubing (Table 7 and 8.) Type El Golpe Field Diameter (inches) Depth (meters) Mud (grams/cm3) Line 16 24 1.08 Surface 9 5/8 400 1.16 Production 6 5/8 2500 1.27 Table 7 Piping utilized in the El Golpe field Type Santuario Field Diameter (inches) Depth (meters) Mud (grams/cm3) Line 16 27 1.10 Surface 9 5/8 500 1.17 Production 6 5/8 3300 1.30 Table 8 Piping utilized in the Santuario field The bits utilized currently are PDC drill bits that have greatly improved the rate of penetration (ROP) of the tri cones bits. The surface control connections, preventers and tree used during drilling operations have a capacity of 5,000 lbs/sq in. The average temperature and pressure of the reservoir ranges respectively between 70 100 Celsius and 250 to 500 kg/cm2 of pressure. 11

Santuario Block, Mature Fields South Region 1.5 Social and Environmental Conditions The current condition of the surface area of the fields in the Santuario Block is modified due to the replacement of the original vegetation by productive human originated (anthropogenic) activities of the last few years. The predominant vegetation now is pastures and agricultural products for autoconsumption. The predominant activity in the area occupied by the field is cattle ranching and therefore the soil shows, in general, a certain level of physical biotic degradation of the habitat and there are very few representative communities of native flora and fauna due mainly to the displacement and destruction of natural habitats occurred in the recent past due to human activity. The strict compliance to certain recommendations, listed below, will assure timely and full completion of the operational programs of the exploitation plan to be proposed and will reduce the associated risks generated by socio political conflicts making more feasible the development of the Carrizo field reactivation project. The recommendations are: mitigating measures, the compliance to established legislation, sticking to safety measures, protection and conservation of the environment, the maintenance programs, the policy of zero discharges and the application of programs of sustainable development for the communities through early management and fair and satisfactory negotiations. From a socio economic point of view, the re activation of the Santuario Block is expected to cause a great positive impact that will benefit the local economy with the hiring of local labor for services and the utilization of low qualified personnel. 2 Development of the Block 2.1 Seismic 2D and 3D The Santuario block is geologically located in the Tertiary Basins of the Southeast. It belongs to the Salina del Istmo sedimentary basin which, together with the other sub basins located in coastal plateau of the Gulf of Mexico (Burgos, Tampico Misantla, Nautla, Veracruz, Papalopan, Comalcalco and Macuspana) belongs to the larger basin of the Gulf of Mexico which is of the passive marginal type. The tectonic history of the basin is related to two (2) major events: the Laramide orogeny that occurred at the end of the Mesozoic forming the characteristic NW SE folding of carbonates and the Chiapaneca orogeny (Miocene) that caused mobilization of salt intrusions and the dolomitization of the carbonate sequences. 12

Santuario Block, Mature Fields South Region Figure 2.1 2D Line, project DR_GPC2D. Map of 2D lines together with the 3D surveys, showing Santuario, El Golpe and Caracolillo fields Subsurface block delineation: The delineation includes wells from the fields Santuario, El Golpe and Caracolillo Is different from seismic delineation, because some wells of Santuario and El Golpe fields are outside of the seismic cubes (below two images of wells there are outside) 13

Santuario Block, Mature Fields South Region Figure 2.2 Seismic delineation of the fields of the Santuario Block Figure 2.2 shows the subsurface polygon and the coordinates of the corners of the Santuario and El Golpe fields. To the left of the polygon, the yellow ovals highlight the wells that are outside of the seismic cube 14

Santuario Block, Mature Fields South Region Figure 2.3 Shows area missing seismic coverage for the fields 17 km2 and 10 km2 15

2.2 Wells drilled, shut in, plugged and in production The hydrocarbon reservoirs in the block are in the Upper Concepcion and Filisola formations. There are 211 well drilled, with 35 active, 73 are either shut in, pending plugging or injectors and 103 are plugged. Currently in the Santuario field there are 18 active wells, 16 flowing and 2 on artificial lift, producing at a total rate of 5,585 bpd of oil and 3.45 MMcfd of gas. In the El Golpe there are 17 active wells, 3 flowing and 14 on artificial lift, producing at a total rate of 1,157 bpd of oil and 0.36 MMcfd of gas. The Caracolillo field is currently shut in. Field Active Wells Shut in with Possibilities Shut in No Possibility Pending Plugging Plugged Santuario 18 4 0 13 29 64 El Golpe 17 22 5 28 64 136 Caracolillo 0 0 1 0 10 11 Total Area 35 26 6 41 103 211 Total Table 2.2.1 Status of wells as of September 2010 for the fields of Santuario Block 2.3 Drilling Results The Tertiary fields are in new phase of drilling, because of recent geological studies supported by 3D seismic and available dynamic analysis. Minor and major workovers, non conventional drilling (deviated, horizontal, multi lateral and double completions) have been started to increase the recovery factors and to construct the infrastructure required for line pipes, collection wellheads and local pipes. The drilling program in the field was successful (Figure 2.3.1) 16

Figure 2.3.1 Sketch of Drilling Pad Santuario 28 H Figure 2.3.2 Development of the field Santuario 17

2.4 Well Maintenance Rig PM 5641 Truck Well Santuario 34 Santuario 28D Figure 2.3.3 Wells drilled Santuario field Maintenance Type Change of Interval Change of Interval Begin End Days Comments Dec 17 09 Jan 06 10 21 Feb 10 10 Feb 27 10 4 Truck Santuario 28D Re shot Mar 26 10 Mar 27 10 2 Truck Santuario 18 Change Of Lift Apr 15 10 Apr 16 10 2 Shot Interval 2693 2698 meters, producing 572 bpd of oil and 0.9 mmcfd of gas Re shot Interval 3408 3412 meters, producing 258 bpd of oil and 0.16 mmcfd of gas, low GOR Re shot Interval 3406 3412, increased production 163 bpd of oil and 0.1 mmcfd of gas Converted to pneumatic pumping (continuous injection with N2) increased production by 384 bpd Table 2.4.1 MAJOR workovers in the field Santuario 18

Rig Well Maintenance Type Begin End Days Comments PM 9105 El Golpe 67 Change of Interval Mar 23 09 Apr 19 10 28 Flowing to Battery, after work PTP=31X5x1/4, producing 383 bpd of oil, 6.29 bpd water, 2.17% water PM 5641 El Golpe 41D Change of Interval Feb 24 10 Apr 21 10 57 Flowing to Battery with Gas injection, after work PTP=5 7X5xFCO, producing 201 bpd of oil, 6.29 bpd water, 3.03% water Table 2.4.2 MAJOR workovers in the field El Golpe Rig Well Maintenance Type Begin End Days Comments Truck Santuario 17T Change Of Lift Feb 16 10 Feb 21 10 6 Begun continuous injection of N2; change to pneumatic pumping, Producing 950 bpd of oil, 0.05 mmcfd of gas Truck Santuario 34T Change Of Lift Jan 28 10 Feb 01 10 4 Weatherford installed mechanical pump unit. Production increase of 107 bpd of oil, 0.05 mmcfd of gas Truck Tupilco 105 Change Of Lift Feb 09 10 Feb 12 10 4 Rehabilitation of mechanical pump. Production increase of 63 bpd of oil, 0.05 mmcfd of gas Table 2.4.3 MINOR workovers in the Block Santuario 2.5 Production History The discovery well for the El Golpe Field was the El Golpe 1 well, drilled in 1963 and produced oil and gas from the A 16 Sand of the Upper Concepcion formation. The first phase of development, between 1966 and 1972, is characterized by the drilling of 87 wells, a maximum production rate of 21,600 bpd of oil and 29 mmcfd of gas was reached in 1971. From 1974 oil production declines and water cut increases (Figure 2.5.1.) 19

Figure 2.5.1 Historical production behavior for the field El Golpe The Santuario field was discovered in 1967 with the drilling of the Santuario 1 well drilled to the depth of 3614 meters and produced oil and gas from the Upper Concepcion formation in the intervals 2,932 2938 and 2,864 2,872 meters. The first phase of exploitation of the field, between 1967 and 1978, was marked by the drilling of 35 wells producing at a maximum production of 10,200 bpd of oil and 7.6 mmcfp of gas in 1973. During the period of 1978 to 1983 oil production declined and water cut increased. The production increases from workovers cannot stop the production decline till 1986. During the period 1996 2000 new workovers were completed to raise production. Later production declined till 2008 when a new drilling phase was started till 2010 and production increased to 6,200 bpd of oil and 3.4 mmcfd of gas (Figure 2.5.2) 20

Figure 2.5.2 Historical production behavior for the field Santuario The Caracolillo field was discovered in 1969 with the drilling of Caracolillo 2 well that reached the depth of 2,850 and produced oil and gas from reservoirs of Miocene age, Upper Concepcion formation, in the interval 2,864 2872 meters. The field was developed between 1969 and 1972, initially to the SW of the discovery well. Maximum production rate of 2,218 bpd of oil and 2.13 mmcfd of gas was reached in 1973. From 1973 production begins to decline until it reaches 52 bpd and 0.13 mmcfd. In June 1992 production stopped. The cumulative production as of January, 1993 was 3.96 mmbls of oil, 5.53 mmcf of gas and 24.0 mmbls of water. Field is currently shut in (Figure 2.5.3) 21

Figure 2.5.3 Historical production behavior for the field Caracolillo 2.6 Infrastructure Facilities Below is the description of the facilities, processes and destination of oil and gas production. Collection Systems: are made of up of pipeline network and surface facilities such as peripheral and general collection wellheads, well lines, oil and gas pipelines of group and of measurement. Processing Systems: are made up of separation batteries, storage tanks, pumping and compression units. At the batteries is performed the separation of gas from liquids, the gas rectification and oil stabilization. The fluids (gas, water and oil) from the wells and collected in the Collection Systems arrive to the batteries heads where they are distributed to the measurement systems or to the separation units. 22

The production infrastructure of the Tertiary fields has an average age of 30 to 40 years, but during the last 10 years it has been optimized to manage the available production. In El Golpe and Tupilco fields, the old batteries (Mecoacán, El Golpe I and Tupilco II), the compression stations (Mecoacán, Tupilco II and Santuario), and the pipeline system were all dismantled. The wells that fed the batteries El Golpe I and Tupilco II became peripheral wellheads that send their production to their respective batteries. Because of the reactivation of mature fields of the Tertiary no other facilities are planned for dismantling. With the exception of the well lines, which are being plugged, the dismantling is done where possible or it is left as is in a way that it does not represent a risk. The production network of the Tertiary area is made up of five (5) separators (Santuario, El Golpe II, Tupilco I, Castarrical and Tintal) from which oil is taken for treatment, conditioning and commercialization to the El Golpe dehydration plant. The gas is separated in the Castarrical, Santuario, Tupilco I and El Golpe II batteries, from where it is sent to compression stations El Golpe and Castarrical, where it is compressed and used as fuel to run the compression equipment, motor pumps and the pneumatic pumping network of the El Golpe and Castarrical fields. Table 2.6.1 Capacity of the Facilities in the Block Santuario 23

Figure 2.6.1 Infrastructure facilities Tertiary fields Block Santuario The crude dehydration plant El Golpe, is located in the Lazaro Cardenas ranch 3rd section, municipality of Comalcalco, between coordinates 18 19 54 of latitude and 93 26 00 of longitude. The facility currently handles production from the Golpe I, Golpe II, Castarrical, Tintal, Tupilco 1 and Tupilco 2 batteries. The oil ultimately is pumped using a 10 oil pipeline to the Dos Bocas port. Infrastructure planned for the well lines of the field El Golpe: Well Begins At Destination Distance (Km) Diameter ( ) El Golpe 10 T El Golpe 10 T Wellhead El Golpe 0.7 4 El Golpe 42 T El Golpe 42 T Construction Cab. Peripheral El Golpe 31 T El Golpe 31 T Construction Cab. Peripheral El Golpe 41 T El Golpe 41 T Construction Cab. Peripheral El Golpe 24 T El Golpe 24 T Construction Cab. Peripheral 24

Other planned infrastructure: Type Begins At Destination Distance (Km) Diameter ( ) Oil pipeline Santuario field Dehydration Plant El Golpe 9.0 10 Oil pipeline Tupilco I Dehydration Plant El Golpe 9.0 10 Figure 2.6.2 Dehydration Tank of 20,000 bls Block Santuario 25

Figure 2.6.3 Diagram of the compression flow field El Golpe (block Santuario) Dehydration Plant El Golpe The liquids (oil and water) arrive from the Castarrical, Santuario, Tupilco I and El Golpe II batteries to this dehydration plant. From the head the fluids are sent to a 20,000 barrels dehydration tank, where the formation water is separated and sent for treatment for later injection to dump (disposal) wells. The oil is sent to two 500 barrel tanks. Later it goes to heaters and to an electrostatic vessel, where finally the dehydration of the oil is done. In the balance tank the main pumps suck the dehydrated oil and send to Terminal of Dos Bocas using a 10 pipeline of 34.3 km. 26

Figure 2.6.4 Flow diagram of the dehydration plant El Golpe Before injection into wells, the produced water from the dehydration of the oil is treated in the El Golpe plant and then, using a transportation network, is injected in the El Golpe field. Figure 2.6.5 Treatment and/or conditioning and disposal of waters 27

Architecture of the oil measurement system installed in the El Golpe dehydration plant: The El Golpe plant has a measurement system for the dehydrated oil in the operations room. The oil is sent to the GOM Terminal of Dos Bocas through the metering skid where parameters such as flow, pressure, temperature, percent water and oil density are monitored. Figure 2.6.5 Water network field El Golpe The production infrastructure of the fields that make up the Santuario block are shown below in tables 2.6.2, 2.6.3, 2.6.4 and 2.6.5. Table 2.6.2 Installed separation capacity of oil and gas 28

Balance Separator Balance Tank 29

Table 2.6.3 Installed gas rectification capacity Table 2.6.4 Installed oil storage tank capacity Table 2.6.5 Installed capacity of gas compression 30

Figure 2.6.6 Pneumatic pumping network field El Golpe Figure 2.6.7 Current Flow network field Santuario 31

2.7 Facilities Management Maintenance of production facilities of PEMEX is conducted in accordance with specific requirements of each type of equipment and its function, with the objective of making operations of the production facilities reliable. It includes facilities such as discharge line to tanks and pipelines, electrical systems, civil works, dynamic equipment and pipelines. Maintenance must be performed periodically and permanently. The three types of maintenance are predictive, preventive and corrective and are scheduled periodically and as required. The following needs to be accomplished: Preventive maintenance of pipelines Re conditioning of pipelines for the runs with instrumentation pigs Preventive maintenance of discharge lines (wellhead to pipeline) WELL Road to Santuario SANTUARIO No. KM. TERRACES KM. PAVED WAYS WELL PAD SEWERS CATTLE BRIDGES BRIDGES 1.550 SANTUARIO 35 0.350 1 0 2 0 SANTUARIO 32 D 0.100 1 1 1 0 SANTUARIO 34, 34 D 0.150 1 0 1 0 SANTUARIO 36 0.550 1 1 3 0 SANTUARIO 33 D 0.300 1 0 1 0 SANTUARIO 15 D 0.000 1 0 1 0 SANTUARIO 31, 31 D 1.200 1 3 2 0 SANTUARIO 28 0.300 1 0 0 0 SANTUARIO 5 0.150 1 0 1 0 SANTUARIO 3 0.100 1 0 1 0 SANTUARIO 13 0.100 1 0 1 0 SANTUARIO 24 0.200 1 0 2 0 SANTUARIO 39 0.350 1 0 2 0 SANTUARIO 101 LACUSTRES SANTUARIO 104 LACUSTRES SANTUARIO 103 LACUSTRES SANTUARIO 106 LACUSTRES TOTALES: 3.850 1.550 13 5 18 0 Table 2.7 Example of Preventive Maintenance program for field Santuario 32

3. Block Potential 3.1 Hydrocarbon Reserves and Cumulative Production As of January 1st, 2010 the certified remaining 3P reserves for the three fields in the Santuario Block are: Santuario 28.4 mmb of oil and 19.0 bcf of gas El Golpe 11.2 mmb of oil and 6.5 bcf of gas Caracolillo has no 3P reserves of oil or gas. Total cumulative production for the three fields combined is 150.7 mmb of oil and 152.4 bcf of gas. Field Reservoir ORIGINAL and REMAINING RESERVES OIL Original Volume Np 1P 2P 3P @S.C. MMb MMb MMb MMb MMb Santuario 8 242.4 54.3 28.4 28.4 28.4 El Golpe 25 315.5 92.5 11.2 11.2 11.2 Caracolillo 47 31.3 4.0 Total Area 80 589.2 150.0 39.6 39.6 39.6 @S.C. = @Surface conditions Table 3.1 OIL Reserves and cumulative production field Santuario ORIGINAL and REMAINING RESERVES GAS Field Reservoir Original Volume @S.C. Gp 1P 2P 3P Bcf Bcf Bcf Bcf Bcf Santuario 8 140.7 40.7 19.0 19.0 19.0 El Golpe 25 208.8 106.2 6.5 6.5 6.5 Caracolillo 47 34.4 5.5 Total Area 80 383.9 152.4 25.5 25.5 25.5 Table 3.2 GAS Reserves and cumulative production field Santuario 33

Field Reservoir Wells Current Production Producing Drilled Oil Gas No. No. No Bpd mmcfd Santuario 47 18 64 5,585 3.45 El Golpe 25 16 136 1,157 0.36 Caracolillo 8 11 0 0 Total Area 80 34 211 6,742 3.810 Table 3.3 Current production oil and gas field Santuario As of January 1, 2010 the Santuario field has cumulative production (Np) of 54.3 mmbls of oil and (Gp) of 40.7 bcf of gas. The El Golpe field has cumulative production (Np) of 92.5 mmbls of oil and (Gp) of 106.2 bcf of gas. The Caracolillo field has cumulative production (Np) of 4.0 mmbls of oil and (Gp) of 5.5 bcf of gas. The well spacing in the Block is 400 meters. 34