bluuebunny/crossref_metadata_2025 huggingface dataset:
Fixed Equipment Integrity
Authors: Velasco Lorena
Published: November 2015

Implementation of Risk-Based Inspection, RBI in production facilities of Repsol Ecuador, is based on the API RP 580 (2009) Risk-Based Inspection, API RP 581 (2000) Risk-Based Inspection Base Resourse Document and API RP 581 (2008) Risk-Based Inspection Tecnology. This RBI methodology allows a first ranking risk level of equipment based on process conditions (qualitative risk analysis). This evaluation is complemented with a thickness analysis and remaining life estimation according to API 510 Pressure Vessel Inspection Code and the API 570 Piping Inspection Code for fixed equipment and piping respectively, and subsequent semicuantitative risk analysis.The thickness measurement and remaining life depends on damage mechanisms wich where identified in corrosion circuits in order to facilitate evaluation and monitoring.

Furthermore, the design criteria, operating conditions, frequencies, technical of inspection and maintenance at different levels of assessment, as well as the application of management policies in different areas such us management of change, risk management, process safety, etc. that are included in the management system factor. This directly affects the probability of equipment failure and allowed us to identify improvement opportunities to strengthen our fixed equipment integrity.

The RBI methodology implementation, has allowed Repsol Ecuador to optimize resources available for equipment maintenance because it prioritizes more critical equipment and allocated resources based on the risk level of each equipment and increase its operational availability to ensure its mechanical integrity since decreases the probability of failure avoiding possible injuries to people, damage of equipment and environment and to increase profitability due to a decrease on the probabilities of shut down of the facilities.
Quantifiable Costs Savings by Using 100% Raw Produced Water in Hydraulic Fracturing
Authors: Ruyle Branden , Fragachan Francisco E.
Published: November 2015

Conventional and unconventional well designs require 50,000 to more than 200,000 barrels of water per well during fracturing operations, generating a strain on fresh water supplies. The strain intensifies in areas where fresh water is scarce, water quality is inconsistent, or it is logistically complex to deliver water to a location. Therefore, having capabilities to reuse produced or flowback water for fracturing applications is a cost-effective option, especially when major savings in produced water disposal costs and reduced treatment requirements are achievable.

This paper comprehensively summarizes the proven benefits of using a bi-polymer crosslinking system that can be used in environments where water quality cannot be guaranteed. In addition, to the cost advantages of using a crosslink system that uses a conventional gelling agent, this paper also demonstrates the yielded cost savings per well that are achievable when reusing 100% produced and or flowback water for hydraulic fracturing operations. The costs cited in this paper are in US dollars.

Produced water typically contains large amounts of dissolved monovalent and divalent salts and other types of ions. Some of the ions present in produced water interfere in the formulation of traditional crosslinking fracturing fluids, and that creates a need in certain systems to mix produced with fresh water in specific percentages. The guar-based system discussed in this paper allows for 100% produced water reuse without filtering or treatment, representing a major environmental breakthrough in fresh water preservation. The new fluid system is a specially formulated bio-polymer crosslinking system that is not affected by produced or inconsistent water quality normally associated with fracturing applications.

The proven robust fracturing fluid system can process 100% untreated produced or flowback water with salt concentration in excess of 300,000 parts per million (ppm), between 5,000 to 30,000 ppm of divalent ions, and greater than 400 ppm of boron and 185,000 ppm of chlorides. The thermal stability of the system is proven to be unaffected by bottomhole temperatures ranging from 120°F to 300°F. The rheological profiles presented illustrate the performance of the fracturing fluid system: It yields higher viscosities than an equivalent traditional borate crosslink fluid system in fresh water. Well treatment results indicate that the bi-polymer system can be accelerated or delayed with proppant carrying/suspending properties comparable to a traditional crosslink system. Permeability tests demonstrate the benign non-damaging nature of the new system that directly represent actual field data with enhanced scale tendency reduction.

In summary, this paper comprehensively reviews the benefits of a robust fracturing fluid that can use 100% produced or flowback instead of freshwater for fracturing operations; that should become the norm as we move into a more environmental friendly paradigm.
Dynamic Under/Overbalance: A Review of the Current Practices in Block 15
Authors: Izurieta A. J. , Davila E. R. , Poveda P. E. , Garcia L. R. , Calpoviña D. E. , Cabezas J. L. , Diaz Hernandez A. , Vallejo R. , Luzuriaga A. , Castro E.
Published: November 2015

Completion with anchored guns instead of killing techniques have been used extensively in Ecuador since 2008, completing 111 works to date only in Block 15. During this process several continuous improvement practices as well as new completion techniques were implemented including:

Job design improvements: Well integrity analysisPenetration and Flow profile analysis on a foot by foot basisOptimization of the current designs by comparing dynamic under/over balance pressure recording with the simulation resultsPost audit of the calculated vs actual productivity

Operational improvements: No fluid loss control used in workover operationsUp to two days of early production due to control fluid does not go into formation.Cost reduction since no special control fluid is used when perforating with static/dynamic underbalance and anchored guns.Minimal fluid loss control when perforating with anchored guns (small overbalanced perforating).New dual concentric completion architecture with anchored guns on the lower sands.The use of anchored guns in reentry wells with 5 ½" casing.Rig time saving when running anchored guns in monobore completionNew perforating procedure in monobore completion by activating anchored guns when ESP is running in hole, then pump is placed to the designed depth, this new operational sequence helped to prevent ESP damage due to high pressure is needed to activate firing head during workover operations when a low pressure reservoir is perforated.

Productivity improvements: Significant reduction in both perforating and completion skins using static and dynamic underbalance.

This paper shows different case studies of completion and perforating designs that enabled to reduce skin as well as completion time in Block 15. A new completion procedure using anchored guns with dual concentric completion is also described.
Well Spacing Index, a New Approach for Planning the Oilfield Development
Authors: González Luís
Published: November 2015

The main objective of this work is to develop a methodology to relate the recoverable oil reserves, with the number of wells required for their extraction, while ensuring maximum economic efficiency and creation of value. The idea of "well spacing index", which is defined as the optimal number of wells to drill or complete per each million of barrels to recover in a specific reservoir, can achieve this goal. This optimum number of wells can be estimated from different perspectives; for example, maximizing the net present value, internal rate of return, the recovery factor or minimizing investment, among others.

This article has as its starting point in the work of R. Corrie (2001), from which the idea of well spacing index is introduced; allowing comparison with many reservoirs simultaneously, regardless of their of dimensions and is especially useful for quick calculations, management, planning, and drilling-portfolio-ranking.

The Well-Spacing-Index calculated from Corrie's equation depend on variables such as the average initial oil production rate per well, the oil prices, the average cost of drilling and completion per well and the discount rate of the operating company; in others words, has a dynamic and changing character, depending on these variables. This not static aspect, allows introducing another concept: "dynamic spacing", which is graphically illustrated in this paper.

For a wide range of data, the WSI varies between 0.3 and 1.3, and an average value of 0.7 is recommended for quick calculations.

It is also possible to determine the well spacing index, to maximize the internal rate of return or investment-efficiency. However, net present value is the objective preferred by many companies. The equations for well spacing index optimizing internal rate or return and investment efficiency is developed in appendix A

No confidential information is published in this paper and data used are from public domain.
Evaluation of Mexico's Shale Oil and Gas Potential
Authors: Stevens S. H. , Moodhe K. D.
Published: November 2015

Mexico has significant oil and gas resource potential in Jurassic and Cretaceous age shale formations. These shale deposits -- which correlate with productive shale plays in the USA -- appear prospective but are still in the early stage of exploration and thus remain poorly characterized. Early shale exploration wells tested mostly low rates, but a recent oil well made 500 bopd while a shale gas well reached 10.9 MMcfd.

The Mexican government plans to offer shale exploration blocks through an international auction. As part of a multi-client study, the authors have greatly expanded the geologic and reservoir data set we developed during an earlier scoping-level study conducted for the US Energy Information Administration (EIA). The additional geologic data support our initial view that Mexico has some of the largest and best quality shale potential outside the US and Canada. Risked, technically recoverable resources were estimated in the EIA/ARI study at 13.1 BBO of oil and 545 Tcf of natural gas.

Detailed geologic mapping and analysis indicates the two most prospective liquids-rich shale areas in Mexico occur within onshore portions of the Burgos and Tampico-Misantla basins, which have transport infrastructure and well services. Significant potential also exists in the Veracruz, Macuspana, Sabinas, and other onshore basins, but those areas tend to be structurally more complex and/or are mostly in the dry gas window.

The U. Cretaceous Eagle Ford Shale (in the Burgos) and correlative Agua Nueva Formation (in the Tampico-Misantla) have high TOC and brittle carbonate-rich mineralogy, but their net prospective area is reduced due to often shallow burial depth and low thermal maturity. A better target appears to be the U. Jurassic Pimienta and La Casita formations, which can be thick (~200 m), at prospective depth over much larger areas, are in the volatile oil to wet gas windows, and frequently overpressured, although TOC is lower than in the Agua Nueva.
Understanding Water Injection From a Control Engineering Approach Using the ERR-OLS Algorithm
Authors: Alvarez J. A. , Wei H. L. , Ibargüengoytia P. H.
Published: November 2015

Using existing production/injection rates is convenient for analysing a mature field as the access to relevant historical records does not cause any extra cost and a large amount of significant information can be extracted from the dataset by means of good analysis methods.

In the proposed work, each of the production wells is considered as an output variable while injection rates from other wells, which have an effect on the outputs, are treated as input variables. Control and System Engineering Approaches motivate such considerations.

Since injection and production are time dependent variables, time delays were considered in the analysis. This consideration allows recognition of how long it takes for the injection on a certain well to affect production.

The Error Reduction Ratio (ERR) algorithm, along with the Orthogonal Least Squares (OLS) method is used to determine how each of the injection wells affects production; this is achieved by sequentially orthogonalising input variables according to the order of their contribution to production.

The algorithm can be customised to explain a certain variance threshold in production resulting from injection wells. For the present case study, a 19-year monthly dataset from Beatrice, an operating field in the North Sea is studied.

It is observed that the historical datasets contain missing values. In order to address this problem, missing values are predicted by using an autoregressive linear model.
Horizontal Well Landing Optimization Combining Rotary Steerable Technology and Deep Azimuthal Measurements in Block 7, Ecuador
Authors: Sierra F. , Teran N. , Bastidas M. , Soria G. , Rojas E. , Villalva R. , Sanchez J. L. , Castro B.
Published: November 2015

Horizontal well landing in block 7 presents several challenges including reservoir vertical position uncertainty, which is generally anticipated based on seismic models, local formation dip at wellbore position and well path construction following strict directional objectives.

To support landing decisions, a logging-while-drilling (LWD) technology based on deep azimuthal electromagnetic measurements was introduced in the project, not only for conventional well-to-well correlation, but to remotely detect the approaching of the latest geological markers and adjust the trajectory inclination and landing point accordingly. In addition, a real-time gamma-ray borehole image was used to qualitatively identify local formation dip for a more effective planning of the further lateral section. Landing section has also been optimized with the use of a point-the-bit rotary steerable system (RSS), which allowed improved directional control, safer operation and higher build rates, minimizing the need of an additional mud motor run to achieve navigation inclination.

This paper presents case studies of the implementation of well placement and directional technologies to optimize horizontal well landing, and the introduction of a novel deep directional resistivity system to eliminate the need of of drilling a pilot hole.
State of the Art in 3D Reservoir Characterization: Palo Azul Field, Ecuador
Authors: Sandoval J. , Gaibor J. , Benalcazar E. , Jimenez L.
Published: November 2015

Redevelopment of mature oil fields is becoming increasingly important, both in Ecuador and worldwide. This paper describes the results of the integration of disciplines in the Palo Azul mature field where leading edge techniques were applied to develop high-definition static and dynamic models, change previous interpretations, and improve the understanding and characterization of the Hollin reservoir to estimate the remaining reserves.

An advanced 3D method was developed that integrates the well log signature, petrophysical analysis, seismic calibration with well logs, horizon correlation, and structural mapping using seismic attributes. Based on this approach, an area of high potential in the northern side of the structure was defined. The Hollin formation was subdivided into three depositional environments: fluvial, tidal-dominated, and marine. For each environment, three primary static parameters were modeled in detail. These parameters include net sand distribution, geometry of the sandstone bodies, and reservoir connectivity.

The static model was critical in providing more meaningful structural information, opening up adjoining areas, and identifying new pay horizons and bypassed reserves. A simulation model was developed to demonstrate the potential of the Hollin formation in Ecuador. Within this formation, defining the location of vertical transmissibility barriers and seal zones was a critical factor in the achievement of good history matching. Based on integrated work between the geology and reservoir engineering teams, several wells were reviewed and updated in the geostatistical model to reproduce, as closely as possible, the historical field behavior. This approach provided a better understanding of reservoir distribution. It enabled the optimization of new drilling locations in the northern area and infill drilling plans for the southern Palo Azul field, reduced the cost of new wells, improved the recovery factor, and enhanced reservoir management.
Multibowl Wellhead
Authors: Mora Esteban
Published: November 2015

Multibowl Wellhead equipment was designed to reduce rig non-productive time and to improve safety during wellhead installation. Nevertheless, this paper presents additional advantages like to use this system in any kind of completion.

The patent pending from Válvulas del Pacífico S.A. goes beyond the advantages of reducing rig nonproductive because it gives the opportunity to the customer in use this any kind of completion in a Multibowl Wellhead and to change one kind completion after evaluation of the well without changing the wellhead basis. For example, change from a single production to a dual system without changing the basis of the wellhead. This is possible thanks to the converter kits.

The Multibowl Wellhead significantly reduces time during drilling of an oil well; time savings are about 18 hours, which implies a significant cost savings. This optimization in time is given by comparing a standard wellhead installation (which is installed in two individual sections) to Multibowl Wellhead installation where both sections are installed altogether. It also improves personnel safety during field operations. Additionally, it is relevant to highlight the versatility of its running tools, since they accomplish at least two functions at once.

Multibowl Wellhead is fully compatible with any type of extraction system; this converter kit can facilitate conversion to an Injector, Re-injector or Dual Concentric. It is compatible with any type and brand of electrical connector used for electro-submersible pumping, as well.

Multibowl Wellhead offers the opportunity to be more cost-effective because it can be used to complete wells where 3 or 4 casing and tubing strings are used, without disconnecting BOP and test it in each section of the wellhead installed and also provides the versatility to use any kind of well completion equipment, like: BES, PowerOil, Natural Flow, Injector, Dual, etc. This innovation has proven been a source of saving for Operators in the range of 5% in rig time per drilled well.
Competitive Analysis of Latin American Oil and Gas Fiscal Regimes
Authors: Vargas J. C. , Quintana S.
Published: November 2015

Mexico's new open market, Brazil's pre-salt discoveries, Argentina's unconventional potential and Colombia's unexplored offshore areas among other examples make Latin America a focal point to global upstream investors. However, in the current low oil price environment resources have become scarce and geological prospectivity is not the only factor to attract investment. Countries are therefore fiercily competing to secure foreign investment and fiscal terms play a key role. This study presents a comprehensive analysis of current fiscal regimes of oil and gas producing countries in the region.

Typical upstream onshore, offshore, heavy oil and unconventional projects are evaluated applying the fiscal terms of each particular country for low, mid and high scenarios (i.e. P90, P50, P10) under identical conditions. Economic indicators such as net present value, profitability index and rate of return for both contractor and government are calculated. Sensitivy analysis is then conducted for low and high price and investment ranges. Government take is calculated depending on the corresponding fiscal system (i.e. Royalty Tax, Profit Sharing Contract and Service Contract) and broken down by its compounded elements (i.e. taxes, royalties, profit oil).

Based on the analysis described above, fiscal regimes of producing countries in the region are compared and ranked by Contractor and Government take. Their behaviour is understood under low and high price and cost conditions in order to estimate the share of the potential upside/downside on extreme cases and subsequently indentify which regimes are more competitive from the fiscal point of view to investors. Finally, elements like fiscal stability and state participation are also incorporated into the analysis.

Recent changes in fiscal terms implemented by governments to either protect their finances against the oil price drop, attract new investors or encourage new developments (i.e. offshore and unconventional exploration) are captured in the present study. Frontier regions such as Uruguay and the Falkland Islands are also included in the analysis.
Work Inclusion Breaking Down Barriers
Authors: Bocchicchio F. , Paz M.
Published: November 2015

SEED is an expression of the spirit of integral and ethical service that the oilfield services company has with its clients and community. The SEED (Schlumberger Excellence in Educational Development) program focuses on education and inclusion for the common good, especially in the vulnerable sectors of society, such as children, youth and people with special needs, and Down syndrome and mental disabilities. Ecuadorian legislation requires that 4% of company staff be people with special needs; nevertheless, the oilfield services company goes further than hiring people from this vulnerable sector. We create true inclusion of people with mental disabilities and Down syndrome in the work, social, educational and professional environment. The Company works with 6 institutions that accept people with various disabilities, and focuses on various aspects of inclusion in education with 3 special education schools in the amazon region. It has provided these schools with technology and training for teachers in technological areas, and how to create projects that focus on solutions for students with special needs and improving teaching for their day-to-day learning. In the case of the Special Needs School, "3 de Diciembre" in Lago Agrio, it has provided them with a physical rehabilitation room with equipment such as: stationary bicycles, electro-stimulation equipment, physical therapy and hydro massage, etc. Regarding inclusion in the work area, along with Fundación General Ecuatoriana and the Vice President's Office of the Republic of Ecuador, and Fundación El Triángulo, we currently have 26 youth with mental disabilities and Down syndrome on our local payroll, and 7 of them work directly in the main offices with the same guarantees and benefits as all of our workers. Regarding sports inclusion, we work with the "School of wheelchair tennis" in Quito. This school provides a space for people with physical, mental and visual disabilities to practice sports.
Dope-Free Technology Improves Health, Safety and Environment Performance of Casing and Tubing Field Operations in Vaca Muerta Play, Neuquen Argentina
Authors: Espinosa C. , Braghieri E. , Actis Goretta E. , Codega D. , Zalazar G.
Published: November 2015

The objective of this paper is to describe the benefits provided by a dope-free technology applied to casing connections ran in the Vaca Muerta shale play, located in the Province of Neuquén, Argentina. The focus is placed on the health, safety and environmental (HSE) benefits obtained during pipe storage, cleaning, inspection, running and post running operations, including waste management.

The method used to evaluate the benefits of the dope-free technology was the comparison of actual operations in the field. Some of these operations ran standard doped connections while others ran connections coated with the dope-free technology. Aspects related to the environment (i.e. water consumption, waste management), health and safety (i.e. risks and their mitigation) were registered. Operations were registered at the rig site and at specific service yards.

The comparison included a complete and thorough analysis of each task and the associated risk for the personnel in charge of pipe preparation, running and storage operations.

The dope-free technology eliminates tasks related to pipe preparation, pipe running and pipe storage, reducing the risk of accidents and enhancing personnel safety.

The dope-free solution is a "zero discharge" technology that reduces water consumption and the generation of effluents. Additionally, it simplifies waste management because the quantity of materials contaminated with dope is significantly reduced.
Case History: Surge Chambers, With or Without Perforating Guns, Conveyed With Wireline or Tubing, Prove to be an Effective Method for Perforation Cleanup, to Increase Well Productivity in the Ecuador Eastern Basin
Authors: Izurieta A. , Garcia L. , Moreno F. , Rios F. , Schoener Scott M. , Harive K.
Published: November 2015

A huge oil recovery opportunity waits in the reservoirs of mature oil fields. Reviving mature oil fields through advancements in oil recovery has opened the doors to renewed hydrocarbon production from wells that have been forgotten because of the natural depletion after years of providing.

One of these advancements is the effect of surging existing perforations using atmospheric chambers to create a dynamic underbalance at the instant perforations are created has been used in other oil and gas assets worldwide to improve production and, consequently, return on investment (ROI). This production increase was achieved with surge chambers to clean existing perforations.

This technology allows producers to obtain sustained higher productivity from their wells at a low cost. This system creates an instantaneous in-situ negative pressure in the wellbore that surges and cleans the perforated interval improving the wells inflow conditions. It is relatively inexpensive to treat a well because it can be deployed on wireline, slickline, jointed tubing, or coiled tubing (CT). These various deployment methods also make this technology available for rigless interventions.

This process uses fast-opening surge vents and atmospheric chamber assemblies that are activated milliseconds after the creation of perforations in the casing and perforation tunnels in the hydrocarbon reservoir. The dynamic underbalance in the wellbore surges these perforation tunnels, enabling the removal of debris and crushed material created by the high energy output of the explosive shaped charges.

This technique can be used to clean existing perforations that have become plugged-off or restricted as a result of scale buildup over time. To achieve this, the vent and chamber assembly are run without the perforating gun assembly.

This technology has been successfully used on rigless wireline operations, and in tubing-conveyed operations. The results have shown that it is possible to regain initial production rates at a relatively low cost as compared to other near-wellbore (NWB) stimulation techniques. This perforate and surge technique has also been used to reduce the operator's cost and time associated with a hydraulic fracturing operation in sandstone reservoirs. In scale-removal applications, this surge technique has been used to successfully remove barium sulfate (BaSO4). To validate these operations, using high-speed pressure/temperature recorders is recommended to capture the dynamic event (Schatz 1999).

In addition to the hardware associated with the vents, chambers, and perforating guns, a software component is used to accurately predict the amount of dynamic underbalance in a specific bottomhole assembly (BHA) to achieve the best perforation cleanup to maximize well productivity.
Fablab Creating a Culture of Innovation in Ecuador
Authors: Bocchicchio Fernando , Paz Manuel
Published: November 2015

As part of the Social and Corporate Responsibility actions of the oilfield services company the first fabrication laboratory (Fab Lab) was created. This scientific-technological program was born from an alliance between the public company, Yachay, and the oilfield services company, and it is a clear indication that they share a passion for learning and science to create opportunities for all youth.

The methodology applies is based on informal learning and the theories of creative thinking. The Fab Lab first appeared in 2000 in the Center for Bits and Atoms (CBA) of the Massachusetts Institute of Technology (MIT). Essentially, it is a laboratory where other laboratories are created. It allows for building machines that are capable of "building almost anything". In Ecuador it involves providing this powerful technological tool and sharing infrastructure, machinery, technology and software with people interested in innovation. This Fab Lab is a space for experimentation within the production fields.

To build the Fab Lab in Ecuador the efforts of MIT (Massachusetts Institute of Technology), the public company, Yachay, and Schlumberger del Ecuador S.A. have come together, and thus there is a wide range of objectives, projects and business models and local planning. The aim is to provide digital development enthusiasts. Practical applications include solar and hydraulic turbines, which help to resolve social problems, including health, agriculture and textiles.

On January 15, during the most important Science event in Ecuador, "INNOPOLIS," within the business venture and innovation framework of 2015 in Ciudad Yachay, the FABLAB was presented with a broad agenda of activities for the general public to learn about the latest innovative tendencies around the world, as well as the scientific projects undertaken in Ecuador.

This system looks to have an impact on the socioeconomic structure of the Ecuadorian society, geared toward a culture of innovation, with creative and proactive individuals, with talents that efficiently contribute to resolving public needs, thereby helping with the transformation of the production matrix in the country.
Experimental Evaluation of a Gas Liquid Axial Cyclone Separator
Authors: Valdez J. G. , Pérez L. D. , Cabello R. , Blanco W. A. , Lombano G. , Segura J.
Published: November 2015

An experimental evaluation of a gas-liquid axial cyclone separator was conducted in a multiphase flow facilities al PDVSA-Intevep, the evaluation of the prototype was executed under controlled conditions of flow rates, between 24 and 60 Bbl/day for a liquid phase and between 80.000 and 190000 SCFD for a gas phase, considering three stator with 45°, 60° and 75° of blade angle in a swirl generator section.

The axial cyclone separator was built in plexiglass in order to record with video camera the phenomenon that was observed inside of the equipment the experimental data of the matrix was collected in a control room, considering the measurement of flow rate, local pressure and the pressure drop in the equipment. The axial cyclone separator consists of a flow conditioning section, as will generator section and a segregation section.

Finally, a total of 72 points were valuated, the performance of the axial cyclone separator was improved with 60° and 75° of the blade angle than a 45° because the collection efficiency was above of 90%, in this study the pressure drop increases inside the equipment 30% when the 75° of blade angle was used in the stator, the best performance was achieve considering the 60° of blade angle in a swirl generator section.
Recognition and Impact of Crossing Conjugate Normal Faults in Amistad Field, Gulf of Guayaquil, Ecuador
Authors: Rodriguez R. , Rodas J. , Chuya E. , Meléndez L. , Romero C. , Gabriela Avila M.
Published: November 2015

The implications and influences of the structural model in hydrocarbon trapping and production have been normally overlooked in the Amistad gas field, located in the Gulf of Guayaquil, Ecuador. As a result of a recent study, crossing conjugate faults were recognized as the main structural style controlling the gas accumulation. These faults consist of normal faults with opposite dips and normally occur in extensional basins where no clear preferential dip direction exists.

The recognition and impact of crossing conjugate faults in Amistad field has been underestimated or not properly interpreted basically due to limitations in quality of the seismic data which leads to the simplification of seismic interpretation. Another important factor worth mentioning is that fault intersection areas are normally not properly resolved in seismic images, therefore leaving room for misinterpretations and misplacement of faults. These areas can also present permeability anisotropy normally increasing transmissibility parallel to the direction of fault intersection.

In Amistad field two main impacts of the interpreted crossing conjugate faults have been observed. The first one is the structural compartmentalization of the field with its impact on production. Secondly, the reduction of the effective reservoir thickness observed in wells inducing to incorrect stratigraphical and sedimentological interpretations of facies changes.

Several examples showing the conjugate fault system, the compartmentalization of the Amistad structure, and the thinning out of the reservoir in several wells will be analyzed and shown.

The recognition of this structural style and its impact will allow Petroamazonas EP to locate in an optimal manner additional infill wells, surface platforms, and the development of still undrilled structural compartments.
Tarapoa West Exploration Project – Integrated 3D Seismic Acquisition, Processing, and Interpretation Solution
Authors: Hu Quan , Zhang Xing , Lin Jincheng , Zhao Xinjun , Wang Yandong
Published: November 2015

The Tarapoa West area in the Oriente Basin of Ecuador was an unexplored area between Fanny-Dorine Field and Shushufindi Field, which was granted to Andes Petroleum Ecuador Ltd. in the 2011 Service Contract negotiation. Very sparse coverage of 2D seismic data and no wells were in the area. Andes decided to acquire 3D seismic over the entire area and merged the new data with existing 3D seismic on the Tarapoa Block to allow an integrated interpretation of new areas and comparison with nearby existing fields and known geological models.

A well planned and executed program consisting of environmental permitting, community negotiations, contractor selection, seismic program design, field testing and acquisition, field processing, final processing, and interpretation all were important, coordinated aspects of creating a successful exploration project in the Tarapoa West Area. Close communication and cooperation of all groups involved from the initial formulation of the concept to exploration drilling and discovery have contributed to a very successful project.

Strictly executed seismic program design and field testing, according to the parameters and imaging of the experiment, and making a comprehensive analysis of the explosives parameters and depths (1.5 kg charge size and single hole depth of 15 meters) obtained better continuity and higher resolution of the effective reflectors. The field records were of good quality and the signal to noise ratio was acceptable throughout the area. A focus on true amplitude recovery, accurate statics calculations and corrections, and accurate velocity analysis during data processing yielded optimal results. The high quality 3D volume allowed us to identify prospects with 4 way vertical closure of less than 5 milliseconds and seismic attribute maps have indicated the lithology distribution reliably. Combining the structure maps and seismic property information maps, and comparing with seismic sections crossing existing oil fields has been useful in calibrating the seismic acquired in the Tarapoa West area. By having a clear understanding of the geological model and target, and by having, from the beginning of the project, close communication and cooperation within the exploration team for the seismic acquisition, including the seismic program design, field testing analysis, processing parameter tests, and procedure design; and for the processing and interpretation phases, a portfolio of reliable, prospective drilling locations were identified. Three prospect trends were found and five exploration wells have been drilled, resulting in TNW, Johanna and Alice west three new fields.

Focusing on the geological target, on seismic acquisition processing and on an integrated interpretation solution has enabled us to not only identify low relief prospects, but also has provided abundant information on lithology distribution. Both aspects have been the key for well location selection.
Energy Efficiency and Greenhouse Effect Gas Reduction
Authors: Zambrano M.
Published: November 2015

Energy management systems help to improve processes and optimize energy use by using available resources and improving efficiencies. Engineering studies that have been done to improve energy use are described in this paper.

– Gas recovery in Block 67 for power generation; this gas used to be burned in the flare stack. The gas recovered passes through a compression system, sending it to the fluid line to be transported to the Northern Production Facility (NPF), hence, avoiding the burning of greenhouse gases. – Energy use optimization in the oil transportation system. Evaluation of the pump performance curves determined that the engine needed to be changed because the installed capacity did not allow optimization. This change decreased energy consumption and improved efficiency.

Simple examples as those mentioned above help to be energy-efficient and to reduce greenhouse gas emissions.
Impact of Connate Water Replacement on Chemical EOR Processes
Authors: Födisch H. , Wegner J. , Hincapie R. , Ganzer L.
Published: November 2015

This paper investigates and discusses connate water replacement during EOR chemical processes in micromodels that resemble porous media. Compared to experiments performed in plugs or cores, micromodels facilitate visual access to the displacement process, hence, enable more detailed process description.

The replacement of connate water during aqueous fluid phase injection is a miscible process. During connate water replacement different regions are observed. (1) A mixing zone (mixture of connate water and injected aqueous phase), (2) a pure connate water zone (3) and a zone composed of injected water, only. The different zones are visualized during flooding experiments by labeling the phases with different types of dye and by using a special experimental setup. To calculate concentration and saturations of the different zones listed above image analysis algorithms have been developed and are presented in this work. These algorithms enable qualitative and also quantitative analysis of connate water replacement.

In areas directly contacted by the displacing aqueous phase (e.g. polymer solution) connate water is rapidly replaced. In areas not directly contacted by the displacing aqueous phase the connate water is fully retained even after one pore volume injected. Only continuing aqueous phase injection leads to a full replacement of connate water after several PV of polymer solution injected. It is remarkable that in these areas the connate water replacement takes place without oil mobilization (increase in oil recovery), indicating that the exchange of connate water and injected water is a diffusive process. Further, the exchange of polymer product into stagnant zones can be seen as a polymer retention mechanism.

The results of this study provide new insights into the fundamental understanding of the impact of connate water replacement on oil recovery during chemical EOR. The use of multiple UV-tracers and a special experimental setup enable clear differentiation between different phases and concentration levels during flooding experiments. Development of image analysis algorithms enable quantitative process analysis.
Sustainability Going Beyond Setting the Direction
Authors: Bocchicchio F. , Paz M.
Published: November 2015

The primary objective of the Corporate Social Responsibility Department of the oilfield services company is to share our complete and sustainable model in the petroleum industry focused toward technical-scientific development of communities through Education. We share our passion for Sciences and learning to create opportunities for youth through the SEED Program, Schlumberger Excellence in Educational Development www.planetseed.com. SEED is a non-profit voluntary educational program. SEED trains students, professors and community members while using Scientific technology and the experience of volunteers to captivate the interest of students with regards to world problems, such as safeguarding water, renewable energy and climate change. Our vision is to Awaken the passion for Science and learning of youth to use their knowledge and technology creatively to increase the possibility for success. We sponsor 5 educational institutions and foundations that work with disabled children and youth in areas, such as labor inclusion, social inclusion and educational inclusion, providing them with equal opportunities. We specialize in training through methodologies, such as LWD (Learning while Doing), in which we use technology, hardware and software from MIT (Massachusetts Institute of Technology), including Go Boards, Makey Makey boards and the Scratch program, where people are trained in digital programming, providing a friendly atmosphere. Another methodology used is the SEED STEM Academy (Science – Technology - Engineering - Mathematics) to foster the interest of youth in matters related to Science, technology, engineering and Math. However, the most important result is the Fab Lab, a joint venture with the public company, Yachay, where we carry out the design, planning, set up, execution, startup and monitoring of the first Fab Lab in Ecuador. Our relationship with the communities goes further than just solidary actions; we have a sustainable program with various stakeholders, including our clients and government entities of Ecuador.
Forecasting Reservoir Management Through Life Cycle Assessment: Case Study Marañón Basin
Authors: Chun N. A. , Bravo R. J. , Quiñones V. A.
Published: November 2015

Integrated management is one of the crucial conditions to determine and carry out an effective monitoring of reserves, which have exogenous and endogenous conditions, valued in oil assets. These assets are strongly influenced by CAPEX, OPEX, volume of hydrocarbons, and oil price; this one last has been affected by a significant volatility in the last period, hauling us an intense slowdown in the short, medium and long-term investment, creating an unattractive risk environment to investors.

A well-structured integrated assessment could give us a greater intensity in investments, provided that the field is considered from a long-term point of view. It must be analyze with the criteria of rate of return, royalty rate assessment and economic effect applying the methodology of the prospective increase in the annual inference (0.650%), monthly (0.645%) and daily. Similarly, those values must be corrected with progressive breaks every five year in the WTI price Forecast, promoting the reduction of risk inherent to the variables of the extractive activity.

For the assessment of a Block which has several million cumulative barrels and proven reserves, it has been considered to fix a reserves replacement rate of 100%. In this sense, a curve that honors 100% refund of reserves each year was plotted. With the right considerations, the international oil price will not be a conditional to stop the life of the projects, and this way for the OPEX in the reduction of staff for operating costs.

The case study is a light/heavy oil field located in the Marañon Basin in the North Peruvian Amazon. The development of this field has adverse conditions in the commercialization of its disaggregated reserves, transportation, logistics, socio-environmental policies, high water cut and specially the use of a traditional methodology of management not according to asset management during its life cycle and its contractual period.

We propose a new integrated management approach for the monetization of active oil assets and the characterization of proven, probable and possible reserves by level of royalties during time contract for the initial financing of the projects. Likewise, design workflows to integrate production information to numerical models, maximizing the value of the asset from short-term measures (optimization of production and workover of wells), medium-term (locations infill drilling) and long term (infill drilling & extension drilling).

A global outlook of the integrated management of the reservoir will give us a great contribution to national production under the criteria of restitution rate and, its transcendental role in the economy of the country expressed in macroeconomic indicators.
Reservoir Tracer Application to Validate a Numerical Simulation Model: An Historical Case
Authors: Gaibor A. , Rodriguez R.
Published: November 2015

IOR techniques represent one of the possible investment opportunities available to oil companies involved in Exploration & Production. An IOR project will only be undertaken if the operator perceives an acceptable balance between the risks and possible rewards.

A project was developed where a reservoir chemical tracer was injected into a heavy oil high permeability infinite acting aquifer reservoir in order to provide experimental information about the connectivity of the interwell zone.

The tracer injection design, execution, sampling, sampling analysis, sampling results, and results analysis are sequentially shown and described. After this the experimental tracer arrival results are compared to those predicted by the available numerical simulation reservoir model.

The results demonstrate consistency between the numerical simulation reservoir model and the tracer arrival time and concentration results. This consistency validates the numerical simulation model and reduces the risk involved in the design of an IOR (polymer injection) pilot project.