bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of Fracture Geometries Utilizing Ultralightweight Proppants Provide Evidence That Partial Monolayers Can Be Created: A Case History
Authors: Chambers R. , Meise K. 
Published: December 2007

Abstract
Recent successes in hydraulic fracturing with ultra-lightweight proppants have led to much discussion and many debates as to why they have been so successful. The theoretical partial mono-layer and the difficulty associated with designing and defining a partial mono-layer in-situ has led operators to examine more fundamental explanations for the success of ultra-lightweight proppants. However, based upon careful examination, highly conductive fractures associated with very low concentrations of proppants, can provide ample evidence that partial mono-layers can be created.
This paper will compare four hydraulic fracture geometries from two wells located approximately 1,700 feet apart. Two fracture treatments were performed on each well, in Clearfork and Glorieta dolomites. The first well was stimulated with conventional fluids and proppants. The second well was hydraulically fractured with a 10 lb/gal brine water and an ultra-lightweight proppant at low concentrations. The objective of the side-by-side comparison was to determine optimal treatments for offset production and injection wells that were to be in-fill drilled.
Fracture geometries for both wells were determined from fracture mapping using microseismic imaging and pressure matching utilizing a 3D hydraulic fracture simulator. Total fracture face surface area, estimated conductivities, and effective fracture half-lengths were compared. The results of the comparisons suggest that there is strong evidence that highly conductive fractures, perhaps even partial mono-layers, can be created with the use of ultra-lightweight proppants in fluids of similar specific gravity.
Laboratory Testing and Well Productivity Assessment of Drill-in-Fluid Systems in Order To Determine the Optimum Mud System for Alaskan Heavy-Oil Multilateral Field Developments
Authors: Davis E. R. , Beardmore D. , Burton R. , Hedges J. , Hodge R. , Martens H. , Svoboda C. 
Published: December 2007

Abstract
The North Slope of Alaska has billions of barrels of heavy original oil in place (OOIP) residing in largely undeveloped reservoirs. Despite this large volume of heavy oil in place, the majority of reserves development on the slope to date has been focused on light crude. However over the past few years, operators have begun to develop the North Slope's vast heavy oil resource base. Recently, an optimum drill-in-fluid/formation damage minimization study was undertaken by ConocoPhillips, BP, and its partners in order to determine the optimum reservoir drilling fluid for the heavy oil sands in order to maximize well productivity and project value.
This paper will provide an in-depth look at the drilling fluid design, laboratory testing, and productivity analysis associated with determining the optimum reservoir drill in fluid (RDF) for the West Sak, horizontal, multi-lateral, extended reach, field development.
Lab test results to be reviewed will include:
Crude Compatibility Lubricity (steel to steel & rock to steel) Shale Stability General Rheology Mud Filtrate invasion tests with core to determine Return Perm Filtercake Removal tests w/ceramic disk tests to determine return permeability and removal effectiveness
With the lab test results, well productivity calculations will illustrate why an oil based mud (OBM) was determined to be the optimum drill-in-fluid for West Sak. Lab tests and inflow performance modeling show injectivity and productivity improvements associated with reducing water based filtrate invasion and permeability reduction due to water and ineffective filtercake removal.
Results show that the overall process of integrating the drill-in-fluid, completion design, inflow performance modeling, and operations procedures should be considered a best practice and an example of how an integrated study ultimately provides a field development with the best project value. Using the current field development economic model, this process added reserves, improved project NPV & IRR and maximized project economics
Light-Oil Air-Injection Performance: Sensitivity to Critical Parameters
Authors: Adetunji L. A. , Teigland R. , Kleppe J. 
Published: December 2007

Abstract
The objective of this study is to determine parameters that have major impact on the recovery from air injection into low permeable fractured chalk reservoirs that produce light oils, such as the Ekofisk field in the Norwegian North Sea.
Earlier works on air injection into light oil reservoirs mainly focused on mathematical modeling of air injection and also on laboratory studies. In this paper, we present results from numerical simulation study.
Results show that when recoveries from low permeability and high permeability reservoirs are compared, recovery is accelerated in the former. In addition, for maximum recovery, air should be injected into all layers containing hydrocarbons. The ultimate recovery from air injection was observed to be insensitive to the amount of water injected during the secondary recovery phase. Also, for optimum recovery, there exists a minimum temperature at which air should be injected, this temperature being a function of the injection rate. Lastly, we observed that residual oil saturation to gas does not have any significant effect on the recovery factor from air injection.
These results are only valid for single porosity systems and may not all apply to dual porosity systems. Also, no economic analysis was undertaken in this study.
Dynamic Flow Analysis of Probe-Type Formation Tests
Authors: Sheng J. J. , Georgi D. , Lee J. 
Published: December 2007

Abstract
Conventional techniques to analyze probe-type formation test data have been based on the principle of pressure transient analysis or on the equations of steady-state flow. The typical techniques are those associated with the spherical and cylindrical flow regimes and with steady-state drawdown solutions. Due to the intrinsic features of probe-type formation tests, such as the flow line storage effect, variable rate history, and short test duration, these techniques in practice have proven difficult to apply or inappropriate. A better suited analysis is based on the simultaneous analysis of both pressure transient and formation rate data. One technique proposed earlier is the dynamic flow analysis with the Formation Rate Analysis (FRA1,2). FRA is based on the linear relationship between the measured pressure and the calculated sand-face formation rate during the test. In some complex flow conditions, however, non-linear relationships have been observed in actual probe tests.
This paper investigates what conditions could cause the non-linear relationship, propose how to analyze such tests, and provide guidelines for repeat tests. To this end, a number of simulated probe-type tests performed under different practical test conditions are used to generate, typical non-linear pressure versus formation rate plots. These non-linear plots may resemble a skewed ellipse, an upward pointing "hockey stick", a downward pointing hockey stick, or a skewed "figure-8". Actual field tests are combined with simulation test data to investigate the conditions that could give rise to such nonlinear plots. Analytical solutions are used to justify the findings in this paper. A number of effects are investigated, including low permeability (mobility), high compressibility, high permeability anisotropy, permeability heterogeneity, upper and lower shale boundaries near the probe, duration of the drawdown, test operation parameters, and plugging and cleaning-up processes.
The methodology and findings presented in this paper can enhance the post-job analysis of formation tests from challenging environments. Based on these findings, test operation parameters can be optimized for repeated tests in real time if the first test reveals pecial non-linear dynamic flow.
An Innovative Geoscience and Reservoir Training Passport for New Recruited Engineers Worldwide as per Sustainable Development
Authors: Coste J. F. , Estival J. , Lecanu H. , Beauchamp M. 
Published: December 2007

Proposal

Abstract
The Oil industry has to face a significant aging of its E&P task force and its correlative retirements in a few years.
In preparation for this crew change, a consistent hiring programme of hiring is being implemented within Total both at the Headquarters and in the affiliates worldwide. Giving these new engineers the required skills quickly poses a big challenge.
Once recruited, every new engineer in Geosciences and Reservoir disciplines is given a Training Passport. In other words, he will follow a personalised curriculum corresponding to about 6 months training distributed over a 2 to 4 year r period.
This road book is designed to fill the gap between initial – on hiring - and expected skills.
For each discipline – i.e. Geophysics, Geology, Reservoir – the technical skills as well as the Personal and Management development objectives are exhaustively listed. An accurate training path comes from a skill list and the training proposal, both in-house and externally. For the Reservoir Engineering discipline, the list contains: HSE, Induction, G&G basics, Well Data acquisition and Interpretation, Well Performance, Reservoir geo-modelling and simulation, Uncertainties integration, Field Monitoring and Management, Economics, Project Management, etc…
During the Passport implementation, the new engineer is assigned to a Technical Department where he can apply what he has just learned through the specific training courses. The training effort represents on average up to 15% of the yearly working time.
Launched in 2003, the Training Passport approach is being extended to all affiliates starting with Western Africa.
The Young engineers Training Passport generates consistency in professional disciplines, and increases visibility and anticipation for all actors involved. It provides the young Headquarters engineers with required autonomy before being assigned in affiliates worldwide.
Because it is a skill driven and a long term process, the Training Passport represents a significant cultural change that efficiently allows us to meet the needs of the Company strategy.
In the Affiliates, the national engineers are trained according to Total international standards. Due to the remoteness from Headquarters, we are experiencing new training technologies, i.e. blended learning, video-conferences, for which the quality of distance coaching is essential for success.
The Training Passport approach contributes efficiently to the Sustainable Development of Hydrocarbon Producing Countries.
Deepwater Horizontal Openhole Gravel Packing in Marlim Sul Field, Campos Basin, Brazil—Completion Project Learning Curve and Optimization
Authors: Acosta M. , Farias R. , Vilela Á. , Mendez A. , Pineda F. , Montanha R. , Garcia E. , Calderon A. , Magno C. , Germino M. 
Published: December 2007

Abstract
Most of deepwater Campos Basin reservoirs, offshore Brazil, have unconsolidated formations that require sand control. Openhole gravel packing has proven to be the effective completion method of choice. The main objectives were to achieve low damage ratios, maximize completion efficiencies and reduce completion cycle times.
The project was conducted in one of the largest deepwater offshore field in Brazil, Marlim Sul. This paper describes the learning curve and completion optimization obtained during planning, execution, and post job analysis of six horizontal wells campaign with five water injectors and one oil producer.
A combination of integrated service lines and experienced personnel were important to achieve excellent injectivity and productivity ratios. Several key operations from drilling to completion contributed to successfully complete these wells: openhole stability, drilling practices, drill-in fluids, wellbore clean-up, filtration, completion fluids, completion tools, sand control, gravel pack software simulator and job execution.
The efficiency of the service company was measured with a system of penalties and rewards allowing the operator to monitor and measure the progress of the learning curve on completion. As final result, the partnership between operator and service companies contributed to more economic completion costs by reducing completion time, and improving well performance.
Fracturing-Fluid Crosslinking at Low Polymer Concentration
Authors: Lie C. , Clark P. E. 
Published: December 2007

Proposal
Crosslinking water-soluble fracturing fluids has been one of the most cost effective technologies developed for hydraulic fracturing. It has allowed these fluids to be used in hostile conditions that would have otherwise required impossibly high polymer concentrations. A great deal of work has been done on crosslinking chemistry and crosslinked fluid rheology and this has led to a better understanding of these fluids. Higher prices for hydrocarbons have taken exploration into more difficult areas and increased the importance of production from existing fields, both of which will require better technologies to economically exploit these reserves. This means that new efforts need to be focused on fracturing fluid improvements
Low polymer concentration crosslinked systems have proven to be extremely effective for both initial and restimulation. The first of these fluid systems were based on zirconium crosslinked carboxymethyl guar. These fluids were effective at transporting proppant and, because of the low polymer concentration, provided low levels of formation damage and quick clean-up. In order to develop the next generation of cost-effective fracturing fluids, a better understanding of the controlling mechanisms for low-polymer concentration crosslinking must be developed.
This paper will describe techniques for characterizing the crosslinking process and crosslinked fluids that will be needed to develop this next generation fluid. We will clearly demonstrate the relationship between the critical crosslinking concentration (minimum polymer concentration where the fluid is crosslinked) and the critical overlap concentration (the minimum concentration for polymer-polymer interaction). In addition, this paper will demonstrate the relationship between crosslinking agent and polymer type to crosslinked gel properties. Most water-soluble polymers exhibit two transitions in the viscosity-concentration curve. The first is the critical overlap concentration and the second is generally recognized as the transition from semi-dilute to concentrated. Concentrations necessary to produce a useful low-polymer concentration crosslinked system are generally between these two transitions and above the critical crosslinking concentration. The useful concentration depends strongly on the polymer and not as much on the crosslinker. All of this information will be used to provide guidelines for the development of future crosslinked systems.
Combining Small Well Spacing With Polymer Flooding To Improve Oil Recovery of Marginal Reservoirs
Authors: Wang J. , Wang D. , Sui X. , Zeng H. , Bai W. 
Published: December 2007

Abstract
Because of low volumetric sweep efficiency and large difference in injection and production rate of each zone, the recovery factor of water flooding is very low in some continental and heterogeneous sandstone oil fields, especially when the reservoir continuity is poor, permeability low and high permeability variation between different zones. Due to the amount of incremental producible oil is not large enough to further drill infill wells economically, drilling infill wells and performing polymer flooding simultaneously was proposed and a pilot test has been concluded.
The paper introduces the laboratory studies on selection of polymer injection parameters and project design optimization. According to these studies, a pilot test of "Combining Small Well Spacing with Polymer Flooding" was conducted. The well spacing is 100 meters, the zones with a thickness of less than 1 meter and with a permeability rage of 5 to 100 md were combined together and put on development. Both lab studies and pilot results show that the volumetric sweep efficiency was greatly increased, especially after applying separate zone injection measures in polymer injectors based on injection profile surveys and tracer test data. The pilot test indicates that the technique of combining infill wells with polymer flooding is economically feasible with 10% OOIP incremental recovery at a production cost of $10/bbl.
Steam-Injection Experiments for Recovery of Heavy Crude Oil of an Iranian Field
Authors: Tabatabaei-Nejad S. A. R. , Shafiei S. , Rajabzadeh S. , Haghlesan A. 
Published: December 2007

Abstract
Thermal methods for enhanced oil recovery account for the large share of the world's production. Steam flooding is one of the oldest commercial methods to enhance the heavy oil recovery. In due respects, experiments of steam injection into a sand pack were performed to study the recovery of heavy oil (API&lt;20) and a lighter oil (API&gt;20) of Iranian field. Two different porosity of sand pack were used and the experiments were conducted with four different types of heavy oil, with different API, to study their effect on recovery. An experimental setup was designed and used to inject the steam into the sand pack. Using different pressures at each experimental run, results show that there is an optimum pressure, which is the characteristic of each reservoir and must be determined by field experiments. The rate of injected steam has an important effect on recovery and an optimum rate exists for ultimate recovery. Steam injection is more effective for heavy oil reservoirs, as for light oil reservoirs; there is the risk of fingering which results in production of steam without sufficient oil production. Even though, in literature, some authors have indicated that the steam injection could be used for the lighter oil reservoirs (API~ 24 or more) but based on the conducted experiments it is proposed to take more care.
A Numerical Technique for Simulating Nonplanar Evolution of Hydraulic Fractures
Authors: Rungamornrat J. , Wheeler M. F. , Mear M. E. 
Published: December 2007

Abstract
A computational technique has been developed for simulating non-planar evolution of hydraulic fractures in three-dimensional elastic media. The technique utilizes a symmetric Galerkin boundary element method to treat the elasticity problem associated with a fracture in an unbounded domain, and a Galerkin finite element method to model the (non-Newtonian) fluid flow within the fracture. The boundary element method is based upon a weakly-singular, weak-form traction boundary integral equation which is applicable to nonplanar fractures in generally anisotropic media. Since the integral equation is only weakly-singular, standard C° elements can be employed, and such elements are adopted everywhere except along the fracture front where a special crack-tip element is used. The fluid flow within the (non-planar) fracture is described in terms of a "channel flow relation" cast in a weak form well-suited for numerical treatment. The final system of non-linear algebraic equations (for the relative crack-face displacement and fluid pressure) is then solved using the Newton-Raphson method. To illustrate the capabilities of the method, example simulations are presented including ones involving complex non-planar crack growth.
Matrix Selection for Conventional and Nonconventional Testing and Sampling in Gas Reservoirs
Authors: Adeyemi O. S. , Edwards M. D. 
Published: December 2007

Abstract
A selection matrix, suitable for discriminating between different techniques for testing and sampling gas reservoirs is presented. The paper provides a quick guide for selecting appropriate sampling/testing methods based on the desired objectives while incorporating operational efficiency, safety/environmental considerations and cost implications. This selection is guided by determining the optimal technique/tool to be e ngaged for obtaining dynamic reservoir properties and uncontaminated gas samples. Thi s can be a great challenge depending on the available technology, reservoir/fluid properties, mud type and economic considerations. The aim is to select a n optimal tool/technology that will meet th e desired objectives without compromising safety and still be cost effective.
This paper is intended to provide a methodology for selecting applicable technology for char acterizing sweet gas (dry/wet) reservoirs, especially during the e xploratory or appraisa l stage. The uncertainties during this stag e make justification for a comprehensive formation evaluation quite difficult due t o high cost or operational concerns.
The paper shows that combining this selection matrix with value of information (VOI) and cost benefit analysis (CBA) will significantly assist project teams in establishing an optimum sampling and testin g program that is f it for purpose. This methodology may result in si gnificant operational savings, especially in high cost environments
First-Time Application in Mexico's Burgos Basin of a New Technology Multistage Completion Process: A Successful Case History
Authors: Centurion S. , Valenzuela A. 
Published: December 2007

Abstract
The Burgos Basin, located in Northern Mexico, is considered by PEMEX to be one of Mexico's major natural gas reserves, and contributes a large portion of the country's current gas production. The basin's gas production comes from a series of sandstone intervals, which are primarily characterized as very low permeability. Consequently, the only way to obtain optimum production rates is using hydraulic fracturing techniques.
Given that all the wells of the basin offer multiple potential productive zones, PEMEX was driven to look for alternative methods and technologies, focusing their efforts on finding the most cost effective completion processes while maximizing the production and returns in the field development.
For years, the conventional completion process used by PEMEX has been PFFP ( perforate-fracturing-flowing-plugging), then moving up hole to the next interval and repeating the process. This process was strongly debated internally for quite some time due to considerable concerns of formation damage caused by fracturing fluids remaining in formation for extended periods of time prior to being recovered. Thus the focus became to modify and optimize each step of PFFP in order to reduce these concerns and their impact on the well's production.
In 2003, a fairly new technology in multi-stage treatment completion process was used. This technique, known as "External Casing Perforating" allowed PEMEX to perforate and isolate individual zones in as little as minutes between stages. As many as 5 zones have been completed within a 30 hour period. The time from completion to production has been reduced from days to hours.
This paper will describe the implementation of this technique in the Cuitlahuac Field, Burgos basin. Most importantly, the case history is substantiated by a comparison with offset wells. The analysis includes the completion processes used, early and normalized gas production and an economical analysis made using both the conventional and the multi-stage processes. In conclusion, the Production Company's perspective about implementing this technology in a massive operation will also be presented.