1. SPE 69582
Field Experiences in Evaluation and Productivity Improvement Using Selective
Hydraulic Fracturing in Deep Directional Wells. Orocual Field, Venezuela
G.A. Carvajal, SPE, K. Ortiz, PDVSA, A. Carmona, PDVSA, G. Parra, PDVSA
Copyright 2001, Society of Petroleum Engineers Inc.
15 % of the planned volume). The hydraulic fractures were
This paper was prepared for presentation at the SPE Latin American and Caribbean Petroleum designed to be carried out in stages, in order to improve the
Engineering Conference held in Buenos Aires, Argentina, 25–28 March 2001.
production profile of the wells due to the high heterogeneity of
This paper was selected for presentation by an SPE Program Committee following review of
information contained in an abstract submitted by the author(s). Contents of the paper, as
the sands combined with a width of 670 ft in average that did
presented, have not been reviewed by the Society of Petroleum Engineers and are subject to not allow the best allocation of the proppant and slug.
correction by the author(s). The material, as presented, does not necessarily reflect any
position of the Society of Petroleum Engineers, its officers, or members. Papers presented at
SPE meetings are subject to publication review by Editorial Committees of the Society of
Petroleum Engineers. Electronic reproduction, distribution, or storage of any part of this paper
Field Description
for commercial purposes without the written consent of the Society of Petroleum Engineers is Orocual Field is operated by Eastern PDVSA EyP through the
prohibited. Permission to reproduce in print is restricted to an abstract of not more than 300
words; illustrations may not be copied. The abstract must contain conspicuous North Unit Management Team, it is located 20 km West of
acknowledgment of where and by whom the paper was presented. Write Librarian, SPE, P.O.
Box 833836, Richardson, TX 75083-3836, U.S.A., fax 01-972-952-9435.
Maturin at the North of Monagas State in Venezuela. The San
Juan Formation is part of the deep Orocual reservoirs and it
represents around 80% the North Unit's total production. The
Abstract San Juan Formation's developed area is divided into four
Until 1998, eleven vertical wells had been drilled in Deep reservoirs, these are San Juan-03, 06, 07 and 09, all
Orocual Field in Eastern Venezuela for a total of 16 hydraulically separated by sealing faults. The San Juan
completions to produce light oil and condensate. By stratigraphic column has been characterized and defined as
hydraulically fracturing these wells, the productivity improved three different hydraulically connected flow units, Lower,
up to three times compared to the initial rates. The use of new Middle and Higher San Juan (see Fig. 1). The reservoirs
technologies in drilling directional wells allowed the contained in the San Juan Formation are medium, light and
construction of three of these wells wells in the San Juan condensate producers with variation of the composition of the
Formation. fluids with depth. The average thickness of the Formation is
This paper resumes the experiences associated to three 650 feet. The OOIP is estimated in 336411 stb. The reservoirs
wells in the Orocual Field, the evolution of operational have been described as volumetric and, to date, only one of
practices and data acquisition that had to be implemented in them is subject to secondary recovery through gas injection.
order to, in some cases, overcome the effect of early stage
screenouts and properly evaluate the productivity of such Geology and Tectonism. The structural model on top of the
wells. Additionally said, experiences allowed the comparison San Juan Formation indicates an asymmetric anticline with,
of the fracturing techniques applied in these case studies, with slightly steeper dips to the south related to thrusting from the
the conventional designs used in the past and to establish the north. The thrust sheet was subsequently cut by one left lateral
best evaluation and stimulation techniques for the San Juan shear fault, separating the Orocual Field into two distinct
Formation wells. structures. The depositional environment was relatively
uniform as indicated by a minimal grain size variation. The
Introduction appearance of the San Juan Formation is a continuous
The drilling of new directional wells in Orocual Field meant a sedimentation in a transgressive system, with the initial
real challenge in the planning and design of the hydraulic deposition of clastic material, coarse type at the bottom and
fracturing activities to be performed on these wells. Based on shale beds occurrences towards the top.
an exhaustive study of the tectonics of the formation, the wells The maximum horizontal stress is oriented in North East-
were drilled with 25 to 42 degrees from the vertical axis in the South East direction. As a result of the collision of the
direction of the minimum stress and in the direction of the Caribbean and South American Plates the Serranía del Interior
maximum stress, to and against the dip of the reservoirs. was formed. The maximum stresses have a preferential
The initial design of the hydraulic fractures in the first direction of 170°. These structural styles make their statement
wells was conventionally planned based on statistical behavior in the main fault patterns in which a pattern of 50 to 60° of
of the previous jobs. In some of the wells, the result was an direction is highlighted, and it corresponds to the direction of
early screenout with little proppant entrance (between 10 and

2. 2 K. ORTIZ, G.A. CARVAJAL, A. CARMONA, G. PARRA SPE 69582
the principal structural feature (inverse faults and anticlines) Perforating Design
with a subordinated direction of 15 to 20° corresponding to The conventional vertical wells were perforated to obtain the
normal faults. most contribution per foot of perforated sand, for this reason
100% of the net interval was perforated, including Lower,
Drilling and Completion Middle and Higher San Juan Formation. This led to a non-
Since 1990, fourteen wells have been drilled in the San Juan homogeneous production profile due to the non-selectivity of
Formation; seventeen of these are vertical wells with double the fracturing jobs. In these cases, the fracturing fluid and the
completions. In the past two years, two directional wells, proppant were displaced throughout the intervals that offered
ORC-29 and ORC-30, were drilled, in San Juan 06 and San less horizontal stress and higher permeability, which in all
Juan 07 reservoirs, respectively. The most important cases, was the most shallow of the intervals and thus the one
characteristics can be detailed in Table 1. with the highest GOR and nearest to the gas-condensate cap.
In search of the best fracture and productivity results, the This non-effective production profile attempted against a
drilling design was made based upon the highest natural rational production of the San Juan reserves.
vertical fracture distribution and the direction of the minimum An initial conventional perforating design was established
horizontal stress. A solid-free drilling fluid was used in 7 and for the deepest interval (zone 1) of Lower San Juan in ORC-29
4-1/2" holes. This fluid provided excellent drilling conditions well (see Fig. 5). During the first Fracture treatment, on this
such as drilling rate, hole stability and adequate rheologic particular interval, there was an early stage screenout,
behavior; it also allowed the use of a fluid with density of 9.5 presumably due to the formation of multiple fractures that
ppg, representing 2.5 ppg less than the usual 11.5 ppg used in inhibited the proppant entrance in the formation. Since this
other San Juan wells. was the only case in San Juan fracturing history and one of the
The direction and incline of the wells were established most deviated wells on the field, the theory of the formation of
considering the dip of the geological structure, the direction of multiple fractures led to the redesign of the perforating
the minimum horizontal stresses and the distribution of the techniques and methods
formation's natural fractures. Due to numerous operational and
production problems presented by double completions and a Shot Hole Phas
Type Selection
new characterization of the reservoir, as three hydraulically density Diameter e
communicated flow units, a 4-1/2"monobore completion Conventional 100 % 6 spf 0,25 inch 60°
design was employed on these new directional wells. Figure 2 Redesign 10 feet 12-18 spf 1,1 inches 60°
shows an example of the direction and incline of the wells.
The perforating of 10 feet of the net pay and the increase
Geomechanical Model of the Reservoir of the shot density and hole diameter in some cases propitiated
San Juan's geomechanical model allowed the description of some control of the mitigation of multiple vertical fractures
the stresses and the characterization of natural fractures. The and high tortuosity effects.
existence of natural fractures in highly consolidated
sandstones (Cf = 6*106 1/psi), specifically in San Juan, has Hydraulic Fracturing Design
been broadly documented in studies and special core analysis, After the selection of the intervals, it was important to
image logs, and fluid loss studies. The geomechanical studies consider the elastic and petrophysical characteristics of the
have proved a variation in the direction of the horizontal rock. These were measured with special logs such as Crossed-
stresses of the formation and the nature of the natural Sonic Dipolar and Spectral Gamma Ray. The following data
fractures. The natural fracture analysis and the regional was obtained from the processing of these logs:
tectonics support a direction of the minimum stress as N35°W
with parallel open fractures toward this direction and closed Young's Modulus = 5,4*10-6 psi
ones in perpendicular direction. Poisson's Ratio = 0.2
The formation's stress field presents a normal regime Porosity = 6%
where the higher stress is the vertical (σv = 1-1,1 psi/ft) and Permeability = 5 mD
the intermediate and minor stresses correspond to the Rock Compressibility = 6*10-6 psi-1
intermediate horizontal stress (σH =0,68 psi/ft) and minimum Invasion radius = 45 ft
horizontal stress (σh=0,65 psi/ft). Temperature = 275°F
The stress field map is shown on Figure 3 where the Net Pay = 50 -220 ft
direction and magnitude of the horizontal stresses can be Vertical Stress = 1-1,28 psi/ft
observed. The directional wells were drilled toward the Horizontal Stress = 9250 psi
minimum stress in order to reduce the drilling days and
operational costs (see Fig. 4). In order to prevent early screenouts and assure the success of
the fracturing job, 10 feet of the net pay were selected; the
choice was based on the best elastic characteristics such as a

3. FIELD EXPERIENCES IN EVALUATION AND PRODUCTIVITY IMPROVEMENT USING SELECTIVE
SPE 69582 HYDRAULIC FRACTURING IN DEEP DIRECTIONAL WELLS. OROCUAL FIELD, VENEZUELA 3
Young's Modulus between 1.2 and 6.8*106 psi and a Poisson's Pore Pressure, psi 7500-6300
Ratio from 0.1 to 0.25 Fracture Gradient, psi/ft 0,43-0,6
The vertical and horizontal stresses were determined by Depth, ft 14000-16000
the following equations: Average bauxite concentration 3,5
Total bauxite, pounds 40.000
σv = 0,007 * ρ * D − Pr ……………………………….(1) Average Conductivity, mD-ft 30.000
ν Bauxite size, mesh 20/40
σH = (σv − Pr ) …………….……………………..(2) Pumping rate, bpm 20
1 −ν
Max. Pumping pressure, psi 10.200
Practical Design Considerations. In very low horizontal Frac. Dimensions (xf, hf, wf), ft 100, 100, 0,2
permeability and very heterogeneous reservoirs, like San Juan,
(Kv = 0.2 mD, Kh = 5 mD) hydraulic fracturing in stages is Formation Evaluation
very important. This technique consists in fracturing, from The evaluation of the wells followed the same procedure for
bottom to top, each prospective interval separately, isolating the most detailed and economical friendly characterization of
the fractured zones after each stimulation. Also, for thick San Juan 07 and San Juan 06. The first pre-evaluation step
sands, it is recommended to perforate only from 5 to 15 ft of was a compilation of the existing information of the reservoirs
the net pay before the stimulation to have better control of the that led to a jerarchical organization of the new information
fracture and then connect the stimulated formation by required for the new wells. Typical evaluation techniques were
perforating the remaining feet with high penetration shots (see used, such as:
Figure 6). In deviated wells, it is difficult to achieve this Buildup Tests. Layer reservoir parameters, such as
connection, which makes it hard to perform this technique permeability and formation damage, were obtained from
successfully. One helpful practice is to locate the perforations pressure transient analysis of build up tests. These tests were
near the top op the shale seal in order to induce the growth of conducted before and after hydraulic fracturing for both initial
the hydraulic fracture from bottom to top. characterization of permeability, skin and reservoir pressure
In naturally fractured reservoirs like San Juan, avoiding to and the resulting parameters after hydraulic fracturing; special
perforate in zones with natural fractures oriented towards the attention was given to formation damage values in order to
maximum stresses has been noted to help prevent early stage evaluate the effectiveness of the stimulation jobs.
screenouts during hydraulic fractures. Production Logs. Production logs were used after each
In order to obtain a more homogeneous production profile fracturing treatment to obtain information of production
and a better fracture the perforated zones were chosen taking profiles of the wells after each fracturing job.
in account the zone with the lowest permeability. Also, using PVT Sampling. Three PVT samples, one bottomhole and
the Neutron Density Logs, the high GOR and gas intervals two surface samples were taken as part of the characterization
were identified and avoided to minimize the gas production of both San Juan 06 and 07.
and optimize the bottom light oil contribution. The approach used in these cases was to obtain initial
Stimulation Treatment. The dimensional design of the reservoir parameters from pressure transient analysis that were
fractures pursued the following characteristics: xf = 90 ft ; Hf compared and validated with previous core, petrophisical and
= 10 ft ; ω= 0,2 inches. The fracture was designed to transient analysis. The evaluation of the fracture job's
overcome the invaded and damaged zone, the Geerstma- performance was achieved through production log tools to
Deklerk equation was used in order to calculate xf. quantify the fluids and the quality of the production profile
after all the stages of the fractures and perforations were
finished.
xf = E * w p …………………………………………...(3)
Field Experiences and Results
To achieve a length of 90 ft, the fracturing pressure design ORC-29 Well. This well was drilled to produce light oil
was 9200 also from the Geerstsma-Deklerk equation: reserves of San Juan 06 reservoir. The initial evaluation and
stimulation design consisted in three hydraulic fractures, two
p' = ( E 3 * µf * qi )1 / 4 / (hf 1 / 4 * xf 1 / 2 )……………….(4) in Lower San Juan and one in Higher San Juan
Lower San Juan.
The conductivity of the fracture was obtained from equation 5: Zone 1. 43 feet of the deepest sand were perforated with 6
shot per foot density. The well produced 190 stb/d with a
choke of 1/4". The initial build-up test showed a typical San
kf * ω
Cdf = ……………………………………………(5) Juan Formation value of skin and permeability ranging from 5
k * xf to 9 mD and a skin factor of 35. For this well, it was possible
to use bottomhole shutdown to reduce the effects of wellbore
The general design of the fractures was as shown: storage for more accurate and reliable results.

4. 4 K. ORTIZ, G.A. CARVAJAL, A. CARMONA, G. PARRA SPE 69582
The hydraulic fracture was made with a pumping rate of the fact that in deviated wells, it is hard to connect the
30 bpm with a 3 ppa proppant concentration. Once the surface fractured interval with the wellbore by perforating the
pressure reached 10000 psi, the fracture was suspended due to remaining zones using conventional practices.
an early stage screenout. Only 20 sacks of proppant could be Results did not show the increase of production that was
pumped into the formation. After this first hydraulic expected by adding one of the most prospective zones of the
fracturing, the well produced 520 stb/d with the same choke well when it is compared with the same choke diameter. This
diameter. can be explained by the known compositional variation of the
As noted before, on the perforation design section, it is fluid with depth that caused an increase on the GOR, mainly
presumed that the early screenout was due to the formation of in Middle San Juan, when the fracture job and perforations
multiple fractures, which inhibited the proppant entrance in contacted the higher part of the structure.
the formation. This brought a about redesign of the perforating
technique being applied. ORC-30 Well. This well was drilled to produce gas
Zone 2: Only 10 out of a total of 47 feet of sandstone were condensate (46° API) reserves of reservoir San Juan 07. The
perforated with a shot density of 12 spf. The previous original evaluation design consisted in hydraulically fracturing
fractured zone (zone 1) was isolated with a gravel plug. Zone three zones, one in Lower San Juan and two in Middle San
2 was fractured with a pumping rate of 18 bpm. 1272 barrels Juan.
of fracture fluid were pumped with 342 sacks of proppant Lower San Juan. For this case only 5 feet of a total of 79
20/40 at a maximum surface pressure of 7400 psi. of Lower San Juan Formation was perforated for the fracturing
Zone 3: Considering the success of the previous job, zone job. Initially it produced 300 stb/d with a choke of 1/4" and
1 and 2 were isolated and 10 of the 43 remaining feet of there were no representative measures of permeability and
Lower San Juan were perforated. The surface pressure raised skin due to operational problems during the bottomhole shut
to 10660 psi and premature screenout occurred rapidly at the down of the well. For the fracture, 410 sacks of 20/40
beginning of the fracturing job; only 22 sacks of proppant proppant were placed in the fracture reaching a surface
were pumped into the formation. This second failure of the pressure of 9200 psi. Due to the poor rock quality of the zone
fracturing job is presumed to have been motivated by a high (5.6 mD and 5.8 % porosity), the small height of the
concentration of natural fractures located exactly on the ten perforated interval, and the small diameter of holes; the
selected feet. These fractures were oriented towards the pumping of the fracturing fluid was qualified as risky because
direction of the minimum stress, generating excessive of the high pressures reached during the fracture. This led to
tortuosity. the search of new or different technologies to diminish these
For production profile characterization, two sets of effects.
production logs were run, one to quantify the contribution of The total production of the well, after the fracturing job,
Lower San Juan by itself, and the other after adding the was 450 stb/d.
Middle San Juan Layers. Lower San Juan alone, achieved Middle San Juan.
1203 stb/d with a highest choke diameter of 3/8". The Zone 1. Based on the experience on previous intervals and
Production log showed a production profile with very low well ORC-29, a high pressure and high penetration type of
contribution from zone 1 and zone 3. It is interesting to note perforation was used on six feet of a total of 108 feet of
how zone 1, after having produced alone 520 stb/d post Middle San Juan Formation. During the fracturing job, only
hydraulic fracture, ended up having almost zero production 159 of the 400 planned sacks of bauxite 20/40 were placed at a
after activating the well with all of Lower San Juan. The entire maximum rate of 20 bpm and a maximum surface pressure of
production of the well came from zone 2 and four added 10600 psi. Screenout occurred an it is presumed that the
intervals above and below this zone. creation of multiple fractures caused the screenouts due to the
Middle San Juan. Only the lowest interval of Middle San high deviation angle of the well (42°).
Juan was fractured at this stage in order to avoid contacting After this second stimulation and the perforation of 102 ft
higher GOR zones or a gas cap. From the interpretation of the of Middle San Juan, the production of the well rised to 730
sonic dipolar and image logs, 10 feet in a zone with low stb/d.
natural fracture density and near the top of a shale seal were Zone 2. Changing in this occasion all the procedures used
chosen. The result was a maximum surface pressure during the in previous jobs, 34 ft were perforated with a shot density of
fracture of 7200 psi and a placement of 297 sacks of proppant 18 spf. The fracture job was done at a pumping rate of 30
into the fracture. Afterwards, 95 remaining feet were bpm and a maximum surface pressure of 8500 psi. Once this
perforated to complete the whole Middle San Juan interval. pressure was reached, screenout occurred achieving to place
The final production log profile was run with different only 235 of a total of 400 sacks of proppant into the fracture
choke diameters, from 3/8" to 3/4", obtaining a total After the addition of the remaining intervals in Middle San
production of 4000 stb/d with a fairly homogeneous Juan, the well reached a total production of 860 stb/d
production profile. It is important to highlight that very little
production was obtained from the added perforated intervals
that were not directly stimulated by the fractures. This proves

5. FIELD EXPERIENCES IN EVALUATION AND PRODUCTIVITY IMPROVEMENT USING SELECTIVE
SPE 69582 HYDRAULIC FRACTURING IN DEEP DIRECTIONAL WELLS. OROCUAL FIELD, VENEZUELA 5
Conclusions 30428, presented at the 1995 Annual Technical
1. In low permeability and very heterogeneous Conference and Exhibition, Dallas, U.S.A., October 22-
reservoirs, hydraulically fracturing in stages is 25.
recommended as a common procedure. 4. Kogsboll, H.H., Pitts, M.J., and Owens, K.A. "Effects of
2. In naturally fractured reservoirs like San Juan, Tortuosity in Fracture Stimulation of Horizontal Wells -
avoiding the perforations in zones with high A case Study of the Dan Field". Presented at meeting
concentration of natural fractures has been noted to held at Offshore Europe held in Aberdeen, Scottland,
help prevent early stage screenouts during hydraulic September 7-10 1993.
fractures. 5. Strubhar, M. K, Fitch, J. L. , Glenn, E.E.. "Multiple,
3. The selection of the zones to perforate prior to the Vertical Fractures from an Inclined Wellbore - A Field
fractures has to be made taking in account the zones Experiment". Presented at the SPE-AIME 49th Annual
with the lowest permeability an nearest to the top of Fall Meeting, Houston, October 6-9.
shally barriers.
4. In deviated wells, little production increase is obtained
from added perforated intervals that are not directly
stimulated by hydraulic fractures.
Nomenclature
ρ = oil density gravity
σH =maximun horizontal stresses, psia
σh =minimum horizontal stresses, psia
σv =maximun vertical stresses, psia
D=depth, ft
Pr=pore pressure, lpc
v=poisson's ratio
P'=maximun pump pressure, psia
Xf= fracture half-length, ft
E=Young's elastic module, psi
w=fracture width, ft
µf=fluid fracture viscosity, cp
qi=fluid pumped rate, bpm
hf= fracture thickness,ft
Cdf=adimensiotal fracture conductivity
Kf= fracture permeability,mD
k= reservoir permeability,mD
Acknowledgments
This paper reflects the work of a large number of people who
have contributed to the accomplishment of the initial
evaluation of the new San Juan wells. The authors would like
to thank the management of the North Exploitation Unit,
PDVSA for their support on the decisions made throughout
the completion and evaluation process of the wells.
References
1. Economides, M., Hill, A. D, Ehling-Economides, C.
Petroleum Production Systems. Prentice Hall, Inc.
EnglewoodCliffs, New Jersey. 1994.
2. Hagist, P., Harry, J., Abass, H., Hunt, J. And Besler, M..:
"A case History of Completing and Fracture Stimulating
a Horizontal Well" SPE 29443, presented at the 1995
Western Regional Meeting. Bakersfield, U.S.A, March
8-10.
3. Hainey, B.W., Weng, X., and Stoisits, R.F.: "Mitigation
of Multiple Fractures from Deviated Wellbores" SPE

6. 6 K. ORTIZ, G.A. CARVAJAL, A. CARMONA, G. PARRA SPE 69582
Table 1: Drilling and Completion Characteristics of wells ORC-29 and ORC-30
Casing
Well Mud Depth Deviation Azimut Completion
Design
20,
Aceite
13-3/8, 9- 14898’-
ORC-29 vassa 9,2 20° 277,8° Monobore
5/8, 15161’
ppg
4-1/2
20,
Aceite
13-3/8, 9- 16448’-
ORC-30 vassa 9,2 42° 115° Monobore
5/8, 15156’
ppg
7
Table 2: Fracturing an Production Results
ORC-29 ORC-30
zone 1 zone 2 zone 3 zone 4 zone 1 zone 2 zone 3
Pumping Rate, bpm 30 18 18 20 25 20 20
Total Saks 21 342 22 297 410 159 235
Early Screenout YES NO YES NO NO YES YES
Oil Rate before 190 NA NA NA 300 NA NA
Stimulation, stb/d
Oil Rate after 520 1200 1350 1600 450 730 830
Stimulation, stb/d
Stimulation Radius, ft 13 95 20 110 120 37 89
Maximum Pumping 10600 7400 10300 7200 9200 10600 8500
Pressure, psi
Closing Pressure, psi 10000 3500 7900 6500 6500 6450 8500
Perforated Interval 43 10 10 10 5 6 34
length, ft
Shot Density, spf 6 12 12 18 18 18 18

7. FIELD EXPERIENCES IN EVALUATION AND PRODUCTIVITY IMPROVEMENT USING SELECTIVE
SPE 69582 HYDRAULIC FRACTURING IN DEEP DIRECTIONAL WELLS. OROCUAL FIELD, VENEZUELA 7
EDAD FO RM AC ION
PLEIS TO CEN O M ES A
FORMACION SAN JUAN
PLIOCE NO LAS
PIEDRAS 3000’
SAN JUAN
6600’ SUPE RIOR
M IOCE NO CAR APIT A
10000’
SAN JUAN
ARE O MED O
I
LOS
OLIG OC ENO J AB ILLOS 12000’
EO CEN O CAR ATAS
13000’
PALEOC ENO V IDO ÑO SAN JUAN
INFER OR
I
CR ET ACICO S AN J UAN
14000’
Fig. 1: Orocual's Stratigraphic Column with highlight on San Juan Formation
Induced Fractures
ORC-29 ORC-30
N S
Natural Fractures
ORC-29
ORC-30
Vertical Well
Deviated Well
Fig. 2: Example of the incline and direction of wells Fig. 3: Seismic line in direction of the dip of the structure

8. 8 K. ORTIZ, G.A. CARVAJAL, A. CARMONA, G. PARRA SPE 69582
Fig. 4: Maximun Stresses Direction from Crossed Sonic Dipolar and Minimus Stresses
where are directioned the breakouts
•EFFECTS:
σ
•Limited Entry.
•Tortuosity Effects. 1Máx
•Multiple Fractures.
σ HMáx
σ Min
100 % perforated interval •Low shot density.
•Small Holes.
•100% perforated interval.
Sreenout
Fig. 5: Conventional perforating design, resulting in formayion of multiple vertical
fractures and early screenout

9. FIELD EXPERIENCES IN EVALUATION AND PRODUCTIVITY IMPROVEMENT USING SELECTIVE
SPE 69582 HYDRAULIC FRACTURING IN DEEP DIRECTIONAL WELLS. OROCUAL FIELD, VENEZUELA 9
Fracture
Propagation
Selected Interval
•High shot density > 18 spf
•Big Holes >1,2”
•Few perforated feet
Fig. 6: Perforating design used after redesign.
DIFERENCIA DE ENERGÍA STONELEY
SÓNICO DIPOLAR CRUZADO
Fig. 7: Stonely wave and crossed sonico dipolar show fracture density zone high

10. 10 K. ORTIZ, G.A. CARVAJAL, A. CARMONA, G. PARRA SPE 69582
Fig. 8: Point select in order to perforating, can see the directions toward maximun stresses of the nature fractures