bluuebunny/crossref_metadata_2025_split huggingface dataset:
How to Reduce Proppant Flowback in High-Rate Wells
Authors: Terracina John , Parker Mark , Pongratz Reinhard , Poole Rob 
Published: December 2007

Abstract
This paper describes the laboratory development and field evaluation of a proppant surface-modification agent (SMA) that increases fracture-conductivity and reduces proppant flowback after fracture stimulation treatments, even in wells with high production rates. This SMA allows proppant packs to withstand three- to five-fold the critical flow velocity required to erode a proppant pack. Laboratory tests indicate that SMA will improve the vertical distribution of proppant by hindering settling. Typically, SMA provides a 15% to 30% increase in proppant-pack porosity. During tests with SMA, fines resulting from proppant crushing and formation fracturing adhered to the treated pack and did not migrate or block pore throats. Fracturing-fluid cleanup was significantly improved when proppant was treated with SMA.
Several field tests were performed successfully with SMA, including fracture-stimulation treatments in the Middle East, where proppant packs were subjected to extremely high flow rates. In all of these tests, proppant flowback was reduced, and well productivity was enhanced. The paper includes designs and results for some of these field tests.
Two New Chemical Components for Sand Consolidation Techniques
Authors: El-Sayed Abdel-Alim H. , Al-Awad Musaed N. , Al-Homadhi Emad 
Published: December 2007

Abstract
Sand production problems are encountered throughout the world and recently detected in Saudi Arabian oil fields. Therefore an increased emphasis is being placed on proper initial well completion as the value of non-renewable oil reserves increases and cost of remedial work skyrockets. Sand control by consolidation involves the process of injecting chemicals into the naturally unconsolidated formation to provide in situ grain-to-grain cementation. Techniques for accomplishing this successfully are perhaps the most sophisticated ones undertaken in completion work.
Many methods have been suggested to consolidate the wall of the wellbore for few inches or feet around the hole. These methods are either expensive or temporarily. This paper introduces two new cheep chemical components to be used to consolidate friable sand formation at temperature up to 300°C. The paper introduces these two components, discusses the physical and petrochemical properties of the consolidated sand and the factors affecting this consolidation and highlight the laboratory process and field application of these two components.
Maintaining Fracture Performance Through Active Scale Control
Authors: Norris M. , Perez D. , Bourne H. M. , Heath S. M. 
Published: December 2007

Abstract
Hydraulic fracturing using proppants is a well established technique for increasing well productivity. However, uncontrolled mineral scale deposition within the proppant pack can result in reduced conductivity and fracture performance, thereby devaluing the initial investment in the fracture. To protect this investment an active scale control strategy is required especially when executed in the presence of a water flood. A number of different techniques have been proposed and used historically, however they have all suffered with one or more drawbacks. These drawbacks have included excessive volumes, poor placement control, short treatment life and / or the potential for fines and sand generation and pack instability. The ability to place scale inhibitor within the voids of a porous proppant offers a robust technique for placing a large amount of scale inhibitor throughout the proppant pack while its controlled released protects the productivity of the fracture.
Previous papers have described the development of porous, scale inhibitor impregnated proppants and highlighted the initial returns from field trials performed on land wells on the North Slope of Alaska. The impregnated proppant technology has now been further developed and two treatments have recently been deployed in the North Sea. The treatments were both designed to stimulate production and to protect the fracture against future scaling scenarios.
This paper will describe the design criteria used to select this method of protecting the future performance of the fracture. In addition this paper will describe the design and execution of the treatments while highlighting the fracture performance and scale inhibitor return profiles generated by recent treatments performed in the British and Norwegian sectors of the North Sea.
Kinetics of CaCO3 Scale Formation. The Influence of Temperature, Supersaturation and Ionic Composition
Authors: Østvold Terje , Randhol Preben 
Published: December 2007

Abstract
A laboratory study of CaCO3 scaling kinetics has been undertaken to obtain information useful for prediction of CaCO3 scale formation. Thermodynamic carbonate scale prediction models have only a limited use since the rate of CaCO3 precipitation can be very slow at lower temperatures (&lt; 60°C). The induction time for precipitation has been determined in a series of experiments where SR, T and the ionic composition of the water from which precipitation occurs, have been varied. The effect of sand from North Sea Oil Field reservoirs on the rate of CaCO3 precipitation has also been investigated by adding such sands to the water under investigation. Our data clearly show that oil field sands enhance the rate, and reduce the induction time for Calcite precipitation. The formation of solid CaCO3 has a window of metastability, which can vary from SR=aCa2+aCa32−Ksp(CaCO3)= 7.0, 2.9 and 2.7 at 80, 100 and 120°C, respectively, with no sand in the water, and 4.8-4.9, 2.7 and 2.6 with sand present. An even more drastic effect was observed when Calcite scale was added to the water. At 100-120°C the precipitation at SR = 1.6 was observed after a few seconds. This is reasonable since the Calcite crystals suspended in the solution act as crystallisation sites for the dissolved carbonate. It was also observed that Mg2+ and SO42- ions in the solution increased the induction time and retarded the CaCO3 crystallisation. The precipitating phase seemed to be Vaterite when Mg2+ and SO42- ions were not present in the solution. Vaterite even started to form on Calcite seeds when these were added to the homogeneous supersaturated solution. This implies that compounds, which block active sites for Vaterite crystallisation, may inhibit CaCO3 precipitation. With Mg2+ and SO42- ions in the solution Aragonite was formed.
High Temperature (374°F, 190°C) Core flooding Experiments for the Selection of Appropriate Scale Inhibitor Products for Potential Application as Downhole Squeeze Treatments in High Temperature Reservoir Environments
Authors: Graham G. M. , Dyer S. J. , Shone P. , Mackay E. J. , Juhász A. 
Published: December 2007

Abstract
In recent years, a number of new HT/HP reservoirs have been developed in the North Sea. The Shearwater reservoir is a gas condensate producer located in Block 22/30 in the North Sea. This reservoir has very harsh downhole conditions as follows: T ~ 370°F, P &gt; 13,000 psi, brine TDS &gt; 250,000 mg/l and is therefore classed as a HP/HT/HS reservoir. Significant downhole carbonate scale ([Ca2+] ~ 20,000 ppm; [Bicarb] ~ 560 ppm) is expected in the wellbore and near wellbore formation area initially at low GWR (GWR &lt; 0.05) with the main mechanism being evaporation from the low volume brine phase into the high volume gas phase. As a result, downhole squeeze scale inhibitor treatments will be required at a very early stage of production. In a previous paper (SPE 60217), presented at the 2000 Scale Symposium, we presented results from a detailed screening study, based largely on bulk experiments (thermal stability, compatibility and performance), to select appropriate chemicals for potential application in this reservoir. Five products were selected which covered a range of generic chemical types including thermally stable phosphonates (HMDP), sulphonated polymers (PVS, S-Co) and phosphorous containing co-polymers (P-SCo).
Further work involving a series of high temperature core flooding experiments conducted at 374°F (190°C) have now been completed on the various pre-selected products. In addition to monitoring inhibitor return profiles, the performance of the released inhibitor species was also examined, with some surprising results. The results from these tests have significant implications on the selection of products for downhole application under such harsh conditions. Results are presented in the following areas: ▪Comparative inhibitor retention and return characteristics▪Comparative field application modelling using SQUEEZE V software▪Implications of adsorption on the thermal stability of the pre-selected products.
Results in this study demonstrate that the rock surface interaction of certain pre-selected chemical species in core flood experiments can alter their performance (as a result of thermal degradation), which was not recorded in the initial static thermal stability tests. This is not in accordance with previously held opinions that adsorption onto rock substrates increases the thermal stability of scale inhibitor products.
The Use of Expandable Sand-Control Technology as a Step Change for Multiple-Zone SMART Well Completion - A Case Study
Authors: Saeby Jan , de Lange Frank , Aitken Scott H. , Aldaz Walter 
Published: December 2007

Abstract
The Champion West (CW) field Offshore Brunei, North Borneo consists of alarge number of vertically stacked hydrocarbon bearing reservoirs where thinlayers of laterally continuous shales are sealing the different hydrocarboncolumns.
Wells in CW are typically completed selectively on multiple reservoirs (3-5zones) due to contrasting reservoir pressures and fluid properties and forreservoir management purposes. Although the reservoir rock is relativelyconsolidated, sand exclusion has been installed on shallower reservoirsfollowing sand failure in offset wells. Internal Gravel Packing (IGP) has inthe past been the preferred sand exclusion technique.
Due to a high deviation in the four CW Early Oil Development (EOD) wells(54-66 deg.), it was desired to incorporate remote operated smart wellequipment to minimise future well intervention requirements.
As the large distance between zones would require up to four IGP operationsper well (resulting in high costs) and would not provide sufficientthrough-bore to install the smart well equipment, it was decided to useExpandable Sand Screens (ESS) for sand control purposes in the new wells. Theuse of ESS facilitates multiple zones to be completed in single installationswhilst providing a larger through-bore for the installation of smart wellequipment.
The paper discusses the sand-face completion design and installationaspects. As one of the EOD wells was completed with IGP, a benchmarking (rigtime, cost, performance) of the ESS technique is also presented. Finally, recommendations are made which should enable further cost reductions in the future.
An Improved Reservoir Characterization of Sandstone Reservoirs in the Khafji Field, Arabian Gulf, by 3D Seismic-Aided Well Test Interpretation
Authors: Watanabe Kazuaki , Nishikiori Nobuo 
Published: December 2007

Abstract
This paper aims to improve reservoir characterization of sandstone reservoirs in the Khafji oil field, Arabian Gulf, by integration of well test analysis and fault location information from three-dimensional (3D) seismic survey.
There are several hundreds of normal faults in the Khafji field which were recently recognized by 3D seismic survey. Although the reservoir has strong edge water drive, water production is observed in some central upstructure area earlier than in peripheral area nearby. Existence of conductive faults, which causes fluid communication between the upper and lower reservoirs, was suspected from engineering analyses conducted. Conductive faults have great impact on reservoir water production and pressure behavior.
The main issues of this paper are: Well test analysis for wells near 3D seismic interpreted faults.Design of interference test to investigate vertical fluid communication through conductive faults between two reservoirs.
Well test data for 5 selected wells located near faults were analyzed and boundary effects such as sealing fault or constant pressure were interpreted. Faults located within 1000 feet distance from wells were characterized by integration of well test and 3D seismic results.
Field test was designed in an area where interference between the Upper Sand and the Lower Sand was suspected. 1 active well and 4 passive wells were designed and pressure behavior of each well was predicted. A fault was defined in the model by placing two adjacent rows of cells with 30 feet difference in depth. Fault conductivity was changed as a parameter in simulation. Two kind of tests were discussed: (1) Short term interference test with 3 pulses of 12 hours each (2) Long term interference test with 3 pulses of 1 week each. Long term interference test was recommended from the simulation results because pressure drop was detectable even when fault conductivity was small.
Innovative Seismic Data Processing Approach to Improve Signal to Noise Ratio
Authors: Gupta P. P. , Prakash Kuldeep , Singh Paramjeet , Lakra M. N. 
Published: December 2007

Abstract
It is a common experience that undesired noise is invariably recorded during seismic data acquisition. The real signal is masked by the noise that may be coherent or random in nature. Coherent noise is generally identifiable by their apparent velocities. The aim of seismic data processing is to identify the noise, attenuate it and improve signal to noise ratio. In this paper, our aim is to remove coherent noise in shot domain before any subsequent data processing is taken up. Although f-k fan filters are commonly used to remove coherent noise by defining fan-like region in f-k spectrum but these are not applied on NMO corrected shot gathers. In our method, NMO correction is applied on shot gathers using reasonable velocities in such a way that primaries are either perfectly corrected or over-corrected and coherent noise remains under-corrected. Since events having different dips in t-x domain occupy separate zones in f-k spectrum, NMO corrected shot gathers are f-k filtered to remove under-corrected events that represent the coherent noise. Data thus f-k filtered is passed through inverse NMO process to remove any changes made to the input shot records during application of NMO correction. Subsequent processing of data is carried out as usual. Significant improvements are seen in data processed with this technique.
The salient features of this technique are two folds. The first is that the NMO correction before f-k filtering widens the separation between real signal and the noise and the second is that the foldage in shot domain remains double of that in CDP domain thus no spatial aliasing takes place.
Towards Environmentally-Friendly Additives for Well Completion and Stimulation Operations
Authors: Rae Phil , Di Lullo Gino , bte Ahmad Atikah 
Published: December 2007

AbstractThe oil and petrochemical industries have unquestionably been key drivers in the development of the complex, modern world we live in. They have helped power our cities, transport our goods and provided the raw materials for the development of countless pharmaceuticals, dyes, plastics and consumer products. In fact, many of the advances made in general health, and in improved living standards around the world, can be traced to the wealth generated by the oil industry. However, while few recognise this contribution, many people do worry about the risks posed by the search for, and exploitation of, hydrocarbon deposits. Indeed, despite its importance, the oil industry has, to some extent, been "demon-ized" by certain groups and subjected to disproportionate criticism. However, while the industry has a generally good pollution record, when compared to other major businesses, there is no room for complacency. Oil itself is usually perceived to be the biggest acute environmental threat, due largely to the volumes involved in occasional, highly-publicised spills and their distressing effects on wildlife. On the upstream side of the supply chain, the escape of oil is still a risk but, in addition, there are many wellsite operations that involve the use of chemical additives. In common with many industrial chemicals, some of these materials are toxic and some may not biodegrade at acceptable rates. With an increasing awareness of the potential environmental impact of chemical additives, particularly in the marine environment, there is a continuing need to develop more efficient, less toxic alternatives.We have been actively pursuing this goal since the early 1990's, replacing many additives with environmentally-friendly alternatives. This has been achieved by combining our knowledge of structure-activity relationships with our knowledge of polymer, surfactant and solvent chemistry and ecotoxicology. As a result of these efforts, many potentially harmful chemicals have been removed from active service and replaced with new, field-proven and eco-friendly systems that have been tested in accordance with OSPARCOM guidelines, or their equivalents. Use of such materials offers benefits in terms of health and safety and, ultimately, potential cost reductions when disposal and waste handling charges are factored in. Use of appropriate materials can even improve job results, as witnessed by several operators, and helps to demonstrate what can be achieved when a commitment to "green" principles is made. However, it should be recognised that there are inevitable development costs in the design, testing and manufacture of new additives. Operating companies need to give due consideration to encouraging and rewarding those suppliers and service companies who, ultimately, help them comply with current and future pollution-control regulations.
Opportunities to Improve Success Rate of Coiled Tubing Operations
Authors: Engel S. P. , Mackey P. 
Published: December 2007

Abstract
Coiled tubing has been an invaluable tool to the oil and gas industry for some forty years. Each time that coiled tubing is rigged up and run into a well it carries with it a risk that the objective of that run will not be met. This paper analyses that risk based on some two years continuous records in the Asia Pacific Region and finds that the average rate of a successful run is 82% over a 23-month period. A database of about 1200 runs demonstrates the type, cause and frequency distribution of failures. Risk management options are reviewed and potential solutions offered.
The cause of failures is most frequently attributed to unknown well conditions. However, inadequate job planning, operator errors and equipment failures also have a significant contribution. The levels of technical complexity demands are escalating. In balance, there are increasing operational skill levels, equipment reliability improvements and a better focus on pre-job planning. This, then, tends to hold the status quo at a constant frequency over time. In order to increase the rate of success, lowering the difficulty of the jobs attempted and/or increasing the operating and equipment reliability will be required. Simplicity and reliability tend to go hand in hand. However, there is a general industry temptation to over-engineer and overcomplicate both the work scope and the equipment. The result may be viewed as unreliable and perhaps, not cost effective coiled tubing solutions.
The opportunity exists to significantly reduce the run failure count. This could be achieved by lowering ambitions and allowing equipment and skill levels to ‘catch up’ with established industry coiled tubing solutions. It then raises the question "Is it better to do something simple well or to risk failure with technical ambition?" This paper concludes that the current failure rate can be improved upon with various corrective actions. This is essential in order to progress to further technical advancements.
Assessment of Permeability Distribution Through Well Test Analysis
Authors: Babadagli T. , Al-Bemani A. , Al-Shammakhi K. 
Published: December 2007

Abstract
Many tools conventionally used in formation evaluation can provide an estimation of reservoir heterogeneity type and degree. Based on this information representative reservoir model can be built through which reservoir pressure and production behavior can be accurately estimated. The estimation of reservoir heterogeneity through reservoir responses, however, is still a challenging task. Well test analyses provide important information about the interwell permeability distribution of a reservoir.
This study aims to correlate the response of pressure transient test to permeability distribution type. For this purpose, correlated permeability distributions in x-y direction are generated using fractional Brownian motion (fBm) as it has been shown in literature that permeability exhibits an fBm type distribution horizontally. 2-D fBm permeability distributions created using mid point displacement method are employed as data to a black oil simulator. Intermittence exponent, H or fractal dimension of the distribution, D, as defined by D=2-H, characterizes the distribution type. All permeability distributions are normalized to represent the same arithmetic mean (20, 100, and 500 mD) and uniform variance so that only their fractal dimension that underlies the smoothness of the distribution distinguishes them. Many different realizations of permeability distributions are generated based on the random number seeds used and pressure transient (drawdown) tests are simulated using a black oil simulator package (ECLIPSE 100). Pressure transient analysis is performed using PanSystem package. As a base case and for the comparison purpose, the same procedure is repeated for totally homogeneous case and random (normally distributed) permeability distribution with the same mean and uniform variance.
The effects of permeability distribution type on the pressure response are clarified. A strong impact of heterogeneity is observed as an increase in skin effect with increasing fractal dimension of permeability distribution. This additional (or pseudo) skin effect due to heterogeneity is correlated to the fractal dimension of the permeability distribution. As a further step, the procedure is repeated for different flow rates applied during the drawdown test. The correlation between the fractal dimension of permeability distribution and additional skin is improved by incorporating the rate into it. The methodology followed can be used in the assessment of reservoir heterogeneity quantitatively using pressure transient response.