Summary The Aguarague field is located in the Devonian basin, northwest of the province of Salta, Argentina. Gas production is obtained from clastics of the Huamampampa formation through an intense network of natural macro- and microfractures. The reservoir is in a north/south-trending symmetrical anticline. Five high-deliverability gas wells watered out between 1991 and 1994; as a result, the field gas production decreased substantially. This triggered a study in 1995 to try to find a means of extending the life of the reservoir. The study indicated that without any modifications, gas production could be expected to continue, at most, until 1999. This paper describes how a detailed fracture characterization led to a dewatering project using gas lift, which significantly reduced the gas decline of the reservoir. The project also brought back to gas production some of the wells that had previously watered out. The 1995 forecast is compared with the actual production performance to date.
The Aguarague field is located in the Devonian Basin, NW of the Province of Salta, Argentina. Gas production is obtained from clastics of the Huamampampa formation through an intense network of natural macro and microfractures. The reservoir is in a North-South trending symmetrical anticline. Five high-deliverability gas wells watered-out between 1991 and 1994 and as a result the field gas production decreased substantially. This triggered a study in 1995 to try to find a means of enlarging the life of the reservoir. The study indicated that without any modifications gas production could be expected to lapse at most to 1999. This paper describes how a detailed fracture characterization led to a dewatering project using gas lift, which significantly reduced the gas decline of the reservoir. The project also brought back to gas production some of the wells that had previously watered-out. The 1995 forecast is compared with the actual production performance to date. Introduction Argentina deep drilling (about 4500m) and discovery of hydrocarbons in NOA Basin, Serranias de Aguarague, Baja de Oran, and Ipaguazu, and in the Devonic and Carbonic sub-basins started in 1951 with the discovery of Campo Duran, a gas condensate reservoir, in the Serrania de Ipaguazu. Madrejones field, north of Campo Duran, was discovered in 1952. The field also produced gas and condensate. A shallower well was drilled in Pena Colorada in 1968. The well produced small oil quantities from the top of the Los Monos formation. Ramos field was discovered in the Serrania de San Antonio in 1977. The field produced gas and condensate from the Huamampampa formation. The Aguarague field, object of this study, was discovered in 1979 with the drilling of well Cu.x-1. The field went on production in 1979 with well Cu.x-2, which produced initially at about 500,000 m3/day from the Huamampampa formation. To date, 16 wells have been drilled, out of which 13 reached the Huamampampa formation. The field reached a production of over 4 million m3/day in 1985. However, five high-deliverability gas wells watered-out between 1991 and 1994 and as a result the field gas production decreased substantially. Figure 1 shows a structural map on top of the Huamampampa formation. Water was advancing from the north in such a way that wells Cu.x-2 and Cu.x1 had watered out by May 1991, well Cu.x-3 by May 1993, well Alo.x-1 by June 1994 and well Sa.Ag.-4 by January 1995. Water was also advancing from the south and well Tr.x-1 watered out in January 1986, well Tr.x-206 in August 1991 and well Tr.x-199 in September 1992. Without any modifications all the wells were going to water out by 1995. Location and Geology The Sierra de Aguarague field is located in the Devonian Basin, NW of the Province of Salta (Figure 2), west of National Route No. 34 near the city of Tartagal.
The Huamampampa formation is one of the best gas reservoirs of Devonian basin located in the North-West of Argentina. In the Aguaragüe field, this natural highly fractured reservoir has produced a large amount of gas, even after most of the producing wells became watered-out. An excellent improvement of gas recovery factor has been achieved by the implementation of an unusual dewatering methodology. The method consists of applying a gas-lift production system to extract water from each flooded well. This type of exploitation causes a delay of the wells water encroachment and an increment of matrix gas production through the wells located at the top of the structure. In this paper we show the benefits of the implementation of this gas exploitation scheme as applied to the field. There have been numerical simulation studies performed in different stages of the exploitation and by different authors. The last study takes into account a vast gas and water production history. Different exploitation cases have been analyzed. The sensitivity scenarios presented here demonstrate the need and the benefits of dewatering. Introduction The Aguaragüe field is located in the Devonian basin to the North-West of the province of Salta in Argentina. This gas tramp is an anticline (Figure 1) originated by forces pushing from the West which generated a number of thrust faults. Huamampampa formation is a gas bearing, low porosity and highly fractured quartzite sandstone. This formation is one of the best gas producers in all the basin. Gas is produced through a network of natural fractures. The formation average section I (with layers BS1, BS2 and BS3), section II (layers BL1 and BL2) and Section III (layers BL3, BL4 and BL5) (Figure 2). BS2, BL1, BL3 and BL5 are the potential producer fractured sands, while the remaining BS1, BS3 and BL4 are considered as not producers layers. Almost all Aguarag e wells completed in Huamampampa produced gas only from layers BS2 and BL1. The field gas production started in 1979, with Cu.x-2 well, which had an initial rate of 500,000 m3/d. Since the discovery, 13 productive wells have been drilled in the structure, reaching a maximum field gas production of 4,000,000 m3/d in 1985 (Figure 3). At this stage the field produced very little water, that is associated to condensed water coming from the gas stream. However, the structurally lower wells had to be abandoned because of a sudden formation water intrusion. Since 1993 the advance of water has been evident and continuous, consecutively flooding wells located in an intermediate position. During the end of 1995 wells started to be converted to water producer through the implementation of an artificial gas-lift extraction system. Currently, only three gas producers remain active, besides a new well (Ag.ap-1001) is about to be completed in Huamampampa formation. At that time, when water started watering out the wells, gas production started to go down very quickly. So, after studies and a numerical simulation, the dewatering methodology was implemented. Thanks to this exploiting methodology we have gotten to keep gas production from crestal wells, and so increase the recovery factor of the field. Present Huamampampa gas production is around 1,000,000 m3/d, with a water rate of 1,400 m3/d coming from dewatering. Lately, we have made a numerical simulation work, which was used to study the reservoir drainage mechanism, dewatering performance and optimization. This model and its results are described below.
TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractThe El Tordillo Field is located in the San Jorge Basin, in southern Argentina, and is operated by Tecpetrol S.A.Realizing this study requires a complex, multi-disciplined approach that allows UTE El Tordillo to describe the reservoir and to develop an appropriate plan to more efficiently use manpower in operating and managing this highly complex reservoir. An essential step toward this goal is developing an integrated structural and stratigraphic model of the reservoirs in the field. These tasks comprise: creating a "living" integrated digital database for the geological, geophysical and mechanical data; making the stratigraphic correlation; identifying all seismically mappable faults and defining the structure of key horizons.Results of these analyses include the following:The Reservoirs Characterization Study produced a digital model that is an accurate and detailed 3-D structure and stratigraphic picture of the entire reservoir volume. Specifically, this model provides a consistent, field-wide, stratigraphic correlation of key horizons that were interpreted using with a high level of integration of geologic and geophysical data. The maps show the field wide distribution, structure and well test results for the 241 individual reservoir sands. Another direct benefit of this study is an enhanced understanding of the 3-dimensional distribution of reservoir units and the controls on reservoir quality. These insights will lead to a better understanding of the production compartmentalization of the reservoir and will help UTE El Tordillo optimize and prioritize development and secondary recovery projects.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.