bluuebunny/crossref_metadata_2025_split huggingface dataset:
Making Sense of the Geomechanical Impact on the Heavy-Oil Extraction Process at Peace River Based on Quantitative Analysis and Modeling
Authors: McGillivray P. R. , Brissenden S. , Bourne S. , Maron K. , Bakker P. 
Published: December 2007

Abstract
The steam injection rates in the CSS operation for the extraction of the Peace River bitumen can be significantly increased by operating at a pressure above the vertical stress of 13 MPa. To improve the understanding of the CSS extraction process, Shell Canada designed and implemented a monitoring program over the most recently drilled production pads. This program included microseismic, surface time-lapse seismic (2D and sparse 3D), a time-lapse 3D VSP, a surface tiltmeter array, and InSAR. Joint interpretation of these data with production data has allowed us to build a conceptual model of the geomechanical response of the reservoir and its effect on the production process.
Dynamic reservoir simulations for Pad 40 were done with the aim to obtain a predictive model. A dilation model from previous simulation work for Cold Lake CSS was applied on the basis of the monitoring analysis and incorporated into the simulations together with a relative-permeability-hysteresis model. A good match of the injection and production volumes, and injection wellhead pressures for the early cycles was achieved using a single well model. Simulation of the later cycles requires a full pad dynamic model constraint by monitoring data, if the heterogeneous steam distribution suggested by the monitoring data becomes significant.
Deviation From Standard Sandstone Acidizing Practices: Chronicle of a Forgiving Acid System
Authors: Obadare A. , Ighodaro O. , Nwoke L. , Onwusika K. , Osadjere P. 
Published: December 2007

Abstract
The process of sandstone acidizing is fraught with the danger of further damaging the reservoir. The odds of increasing formation damage is raised if standard acidizing practices are not followed primarily due to non-technically related issues like logistics.
This paper reviews the stimulation of two low-pressure oil producers and another oil producer, which was previously producing below potential. Standard practice indicates that a HF based system be flowed back or lifted with nitrogen to reduce the risk of additional formation damage due to factors including emulsion / sludge / secondary precipitate formation.
For these case histories, the residence time of the acid in the reservoir was between 18 hrs to 96 hrs due to the non-availability of nitrogen and poor well inflow. The remarkable aspect of these operations was that there was no evidence of further impairment in all the wells. In fact, two of the wells demonstrated superior performance after production rate stabilized. These successes are partially attributed to the unique chemistry of the retarded acid system, favorable rock mineralogy, exhaustive lab testing / field QC, the presence of an acidic over flush and the use of additives that prevented formation of emulsion and sludge.
This acid system can be used in depleted / low GOR reservoirs where over-displacing is a poor option in the absence of flow-back aid and also for single stage acidizing in low carbonate sandstone reservoirs.
This paper attempts to follow through the process of candidate selection with a focus on nodal analysis. It also defines the factors affecting success rates in the stimulation of depleted reservoirs, offers a superior acidizing system for mitigating the effect of deviations from standard acidizing practices and reinforces the possibility of single step sandstone acidizing (with a brine cushion ahead) especially in low carbonate content sandstone.
Aqueous Discharges From E&P Installations: Current Technical and Regulatory Challenges From an Operator's Point of View
Authors: Garland E. , Prunier A. 
Published: December 2007

Abstract
The regulatory regime applicable to the onshore discharge of aqueous waste streams generated by Exploration and Production (E&P) facilities differs from the one(s) applicable to offshore discharges.
The example of the European Union framework Directives shows the importance given to the characteristics of the receiving environment when regulating onshore discharges, while offshore, the regulatory regime, led by international (MARPOL) or regional conventions (such as OSPAR or the Kuwait Convention), primarily focuses on the source of the aqueous discharges. Today, offshore regulations are a compromise between aspirational goals and practicalities, as the recent development of interpretation of MARPOL rules regarding FPSOs and FSUs shows.
The second part of the paper describes the basic principles developed by TOTAL to elaborate a realistic and sustainable position when regulations fail to provide sufficient guidance. Key widely accepted international conventions serve as a basis for internal standards while provisions of the regional conventions guide us when elaborating local standards for a specific installation, together with due consideration to the actual or forecast impact of aqueous discharges to the environment.
Results of a Laboratory Propellant Fracturing Test in a Colton Sandstone Block
Authors: Wieland C. W. , Miskimins J. L. , Black A. D. , Green S. J. 
Published: December 2007

Abstract
The use of high energy material to stimulate production has been practiced in the oilfield since early in the industry's history. While the materials used for stimulation have progressed from explosive materials to propellants, the basic concept remains the same. A highly energetic material is burned in the wellbore and the gasses and energy released cause the rapid pressurization and breakdown of the formation. This breakdown is capable of generating multiple fractures with certain geometric properties.
To investigate and confirm the generation of propellant induced fractures in low permeabililty formations, a large scale laboratory test was designed and conducted at the TerraTek, Inc. laboratories in Salt Lake City, Utah. The test was conducted on a 30"x30"x36" Colton Sandstone block that was loaded in a poly-axial stress frame to predetermined reservoir conditions. A scaled wellbore, drilled in the center of the block, contained the propellant charge. After the block was properly stressed, the propellant charge was deflagrated. The block contained several pressure probes imbedded in the block and located in the wellbore that were capable of sampling at extremely high rates (milliseconds) to capture the full response of the propellant burn.
Upon completion of the deflagration, the block was removed from the test frame and cut horizontally to examine the fracture pattern generated by the propellant burn. Each half was later split along the primary fracture to examine the height growth and fracture lengths generated by the propellant stimulation.
This paper discusses the test design and execution, the resulting fracture geometries and analyzes the pressure responses witnessed during the propellant deflagration. The results show laboratory verification of some propellant fracture theories and provide insight to the effects of propellant deflagration in field applications.
Development of a Generic Life-Cycle Modeling Tool
Authors: Woodhead T. 
Published: December 2007

Abstract
The Shell integrated modelling tool ‘HFPT’ (Hydrocarbon Field Planning Tool) has been used to generate a generic single life cycle model in which the appropriate business focus at each stage of the business cycle is maintained.
This model has been applied to two very different development projects, the first being a single oil field multiple reservoir development and the second a large integrated multi-field gas node, both in the Niger Delta. In each case, the tool was successfully used to evaluate alternative business developments using multiple scenario modelling techniques.
The model results show the capabilities of the tool in providing a focus on the business decisions required at key stages of the development life cycle and the ability of the tool to provide the appropriate amount of surface and sub-surface detail for addressing the development decisions to be made at each stage
The Shell integrated modelling methodology places a strong emphasis on achieving the appropriate focus at each step in the business cycle. In particular, the net is cast wide at the ‘feasibility’ stage requiring large numbers of development opportunities to be evaluated using simple or coarse modelling. As the project progresses, there is a requirement to add detail and to develop more complex models as the project moves towards concept selection. The smooth and seamless transition between these stages has always been an issue and has typically lead to the use of ad-hoc tools at the feasibility stage with the requirement to later re-derive and confirm these results from scratch using detailed models. The new tool promotes a true ‘life cycle’ modelling approach to asset development and a robust audit trail between each of the different levels of modelling
Achieving Zero Accidents in Marine Stimulation Vessels
Authors: Mayor L. , Boing O. , Santos A. 
Published: December 2007

Abstract
Operations of marine stimulation vessels are considered a highly risky activity, by the standards of oil and gas industry. Activity performed by these vessels include acidizing, hydraulic fracturing, scale, asphaltene, hydrate, water, and sand control. The inherent hazards related to the nature of manipulated fluids involved on these different scenarios, comprised by acids in different strengths, non aromatic solvents, chemical inhibitors, and the pressure under which they are usually pumped into an oil or gas well, added to vessels navigation hazards such as potential leaks, sea and weather conditions, contribute to the risk involved.
In addition, confinement created by lack of space, and the need to run simultaneous work, such as pumping and maintenance on the stimulation plant, add to the overall risk, involving health, safety and environmental components. It is like having in the same site the Base Plant and the Well.
Exposure to chemicals, relatively high noise levels, weather conditions and stress due to marine confinement is a daily reality to the workforce. Simply there is no room for mistakes.
To control and minimize these risks, oil industry has applied intense efforts. Incorporation of new technologies, development of better personnel protective equipment, improvement of procedures and workforce training/qualification are concrete examples of these efforts.
Specific management tools have also been applied in the search of an accident free environment, and are mentioned on this paper. Additional efforts will be required to continue running a zero accident environment. These efforts include the development and maintenance of a high level culture with focus on human behavior.
This paper describes how the application of a safety culture, together with traditional safety management tools ended accidents and allowed achieving two consecutive years without accidents by two marine stimulation vessels operating in Brazilian coast, Macae Basin.
Critical Issues in CO2 Capture and Storage: Findings of the SPE Advanced Technology Workshop (ATW) on Carbon Sequestration
Authors: Imbus S. , Orr F. M. , Kuuskraa V. A. , Kheshgi H. , Bennaceur K. , Gupta N. , Rigg A. , Hovorka S. , Myer L. , Benson S. 
Published: December 2007

Abstract
Carbon dioxide capture and storage (CCS) is emerging as a key technology for greenhouse gas (GHG) mitigation. The Society of Petroleum Engineers (SPE) Applied Technology Workshop (ATW) on CO2 Sequestration (Galveston Island, Texas, Nov. 15-17, 2005) convened a diverse group of geoscience, engineering, economics and stakeholder experts to review the status of CCS and to identify the remaining critical issues that still serve as barriers to its acceptance and widespread deployment.
Site assessment can be improved with systematic, generally accepted approaches that identify and focus on injection, capacity and containment risks. Reservoir simulation models can be adapted from oil and gas applications but further experimental work and code development are needed to quantify the role of major CO2 trapping mechanisms. Enhanced hydrocarbon recovery accompanying injection of CO2 is well established for CO2 EOR but its efficacy in EGR and ECBM is unclear. Well integrity, a key vulnerability in CO2 storage, should be addressed through modified well materials and construction approaches and cost effective remediation and intervention techniques. Field management issues, including risk assessment and monitoring, would benefit from development of accepted practices to apply through project lifecycle.
Overall, the Workshop participants concluded that implementation of CCS, in a timely manner, represents a complex challenge that requires coordination of technical expertise, economic incentives, appropriate regulations and public acceptance. Storage assessment tools are available and adequate, although in need of refinement and standardization. Capture technology, however, requires more intense research aimed at new technologies and deep cost reduction. Infrastructure and regulatory development needs to reflect expectations and incentives from government bodies. Early implementation of CCS is expected to focus on the gas processing and other industries that produce high purity CO2 with storage in local hydrocarbon reservoirs or saline aquifers. Deployment at a scale required to substantially reduce CO2 atmospheric concentrations, however, would rely heavily on injection into saline formations and take decades of investment to build the extensive infrastructure required to capture and transport CO2 to injection sites.
The ATW gathering was a unique, timely opportunity to engage experts in an assessment of the status and best path forward for CCS.
Recovery of Oil Resources from the Residual and Transitional Oil Zones of the Permian Basin
Authors: Koperna G. J. , Melzer L. S. , Kuuskraa V. A. 
Published: December 2007

Abstract
Because of their low to moderate oil saturations, the immobile (but significant) oil resources in the transition and residual oil zones (TZ/ROZ) are not economic to produce using primary/secondary oil recovery techniques. As such, the great majority of domestic oil wells are completed at the first evidence of mobile water (oil-water contact) above the TZ/ROZ. Outside of a small group of forward-looking operators, little is known about the ability to target and produce this large TZ/ROZ resource. However, in the current economic climate and with technology advances, the TZ/ROZ resource offers a new source of domestic oil production. The relatively thick (100s of feet) TZ/ROZ located beneath the traditional main pay zones of Permian Basin oil reservoirs provides an attractive domestic development resource.
Carbon dioxide (CO2) enhanced oil recovery (EOR) is a viable technique for recovering immobile residual oil left behind ("stranded") after waterflooding. Further, the oil saturation in the TZ/ROZ portion of a reservoir is often similar to the oil saturation left after waterflooding. As such, with progress in CO2 flooding technology and availability of affordable supplies of CO2, the oil in the TZ/ROZ could become an economically viable target.
This paper will provide updates for four key TZ/ROZ projects (two in the Wasson oil field, one in the Seminole San Andres Unit and a fourth at Salt Creek). These pilot projects plus reservoir simulation work by the authors show that this residual oil can be efficiently recovered using CO2-EOR. The paper discusses how two CO2-EOR practices, selective completions and joint development with the main pay zone, would enable the recovery of the TZ/ROZ resource to be optimized. The paper concludes with an assessment of how much resource potential in the TZ/ROZ may hold for future oil development with the Permian Basin.
Scatter Search Metaheuristic Applied to the History-Matching Problem
Authors: Sousa S. H. G. , Maschio C. , Schiozer D. J. 
Published: December 2007

Abstract
Reservoir simulation plays an important role in managerial decisions during the life of a reservoir, so it is vital that they present an accurate prospect of real reservoir performance. The main goal of the History Matching (HM) process is to improve the quality of numerical models by constraining simulated to observed data. A typical HM process evaluates a chosen objective function (OF) comprised by linear functions on the uncertain reservoir properties. The OF can be modeled in such a way that the HM process can be solved as an optimization problem. This paper discusses how the Scatter Search (SS) technique can solve the HM problem. The main feature of SS is that it works on a set of solutions called the reference set (RefSet). The idea is to improve the overall quality of the RefSet. New solutions are generated by a non-convex combination of explored solutions. The goal of this paper is solve the HM with SS and to evaluate its performance.
The proposed methodology was tested with two base synthetic reservoir models. The first is a homogenous reservoir with 8 different horizontal permeability regions, while the second is a highly heterogeneous reservoir model where low quality background sand is crossed by high permeability canals. The results show that SS was quite efficient, considering the quality of the generated solutions and the number of required numerical simulations.
Most of the current HM methodologies do not perform well when the solution space is large and complex. The application of the SS methodology to the HM problem is a novel approach. Unlike most metaheuristics, SS can be effective even when the simulation time of each tentative solution to the problem is long.
Mechanical Automation in the Oilfield To Help HSE Programs
Authors: Ross S. E. , Havalda R. A. , Havalda P. A. 
Published: December 2007

Abstract
This paper attempts to address the continuing occurrence of major HSE incidents in the Oil Industry with emphasis on the trend of automation to help reduce these expensive and lethal incidents.
Today we cannot imagine a machine shop or the automobile industry operating without computerized or robotic controlled machinery (such as the common CNC system) to turn out high precision mechanical parts and our fancy cars that we drive everywhere any day of the week.
It took awhile but the task of automation has started to make its way below the rotary table on the drilling rig. The computer is now handling functions handled traditionally by the Directional Driller.
Rotary steerable tools that are comprised of articulated connections and adjustable angle stabilizers run behind the bit now routinely allow the Oil Industry to weave a directional well from vertical to horizontal to even more severe angles while operating tens of thousands of feet from the drilling rig and tens of thousands of feet below the earth's surface.
With the continuing increase in marginal field developments particularly in the North Sea, there has been a continuous trend towards unmanned facilities to reduce operating cost and reduce safety related incidents.
The recent refinery incident in Texas for BP and the loss of the entire Piper Alpha and Bombay High platforms in the North Sea and the Indian Ocean are major capital losses coupled with injuries and loss of life.
Most everything in life has risks attached and our operations in the Oil Industry have especially higher risk due to the precious but highly flammable hydrocarbons that we find, produce, refine, and market for world consumption.
Thanks to higher prices for oil and gas, producing the higher risk oil and gas fields which were once before deemed uneconomic will now find their way to market. Without comprehensive HSE programs that include automation, history's major incidents will continue to shock our industry and many families alike.
Effect of Non-Darcy Flow on Well Productivity of a Hydraulically Fractured Gas/Condensate Well
Authors: Mohan J. , Pope G. A. , Sharma M. M. 
Published: December 2007

Abstract
Hydraulic fracturing is a common way to improve productivity of gas-condensate wells. Previous simulation studies have predicted much larger increases in well productivity than actually observed in the field. This paper shows the large impact of non-Darcy flow and condensate accumulation on the productivity of a hydraulically fractured gas-condensate well. Two-level local grid refinement was used to so that very small gridblocks corresponding to actual fracture width could be simulated. The actual fracture width must be used accurately model non-Darcy flow. An unrealistically large fracture width in the simulations underestimates the effect of non-Darcy flow in hydraulic fractures. Various other factors governing the productivity improvement such as fracture length, fracture conductivity, well flow rates and reservoir parameters have been analyzed. Productivity improvements were found to be overestimated by a factor as high as 3 if non-Darcy flow was neglected. Results are presented that show the impact of condensate buildup on long-term productivity of wells in both rich and lean gas condensate reservoirs.
A Digital Pressure Derivative Technique for Pressure Transient Well Testing and Reservoir Characterization
Authors: Veneruso A. F. , Spath J. 
Published: December 2007

Abstract
The pressure derivative has become the primary interpretation tool for diagnosing well and reservoir behavior. In many situations however, the derivative of the measured pressure data is uninterpretable or, worse, mis interpreted because of various artifacts collectively termed noise. While various noise-smoothing techniques have been used, there are valid concerns that smoothing procedures may adversely affect the well-test interpretation. In contrast, measurements from new pressure gauge systems can now provide the stability and resolution required to characterize/quantify complexities of the well/reservoir system, which may otherwise have gone unnoticed.
In this paper we endeavor to reconcile the advances in well-test interpretation and in measurement technology. Specifically, we describe a new technique for differentiating well-test-pressure data, the digital pressure derivative technique. This approach produces the most accurate and representative dp/dt curve by incorporating knowledge of both reservoir and pressure-gauge physics. This technique is efficient and straightforward to imp lement and may be used on both real-time and recorded data. No modifications to gauges or other hardware are necessary. The technique enables analysts to customize the differentiation based on the measured-data quality without a need for subjective smoothing algorithms. Examples are presented using field measurements to illustrate the technique.