bluuebunny/crossref_metadata_2025_split huggingface dataset:
Integration of Streamline Simulation and Automatic History Matching
Authors: Maschio Célio , Schiozer Denis J. 
Published: December 2007

Abstract
This paper presents an integration of different methodologies for history matching of complex fields. For such cases, a fine grid model is necessary and, therefore, the simulation time is high, yielding a constraining factor because the number of simulations must be limited in such cases in order to turn the process feasible. The proposed approach combines three fundamental steps: (1) a global history match; (2) the use of streamline simulation to determine flow path among producers and injectors or between an aquifer and a producer well to facilitate the choice of regions of interest to history match individual wells; and (3) the history match of wells through the modification of the properties of the regions of interest. The first and third steps are performed using an automated history matching methodology, which uses parallel computing and traditional simulation procedure.
The proposed approach is applied to a real case from an offshore field with 34 producer wells and 13 injector wells and a period of 22 years of production is available. Results showing the advantages and disadvantages of using an automated history matching in a complex field are presented. The use of streamline simulation as a support tool in such complex field history matching is also presented. Other aspects such as speedup of the process, using parallel computing, and high reduction rate of objective-function, by choosing correct regions for modification of the properties, are described in the paper.
The main contribution of this paper is to show a convenient form of combining two important tools: streamline simulation and automatic history matching of complex fields.
Field Experiences with Assisted and Automatic History Matching Using Streamline Models
Authors: Cheng Hao , Wen Xian-Huan , Milliken William J. , Datta-Gupta Akhil 
Published: December 2007

Abstract
Reconciling high-resolution geologic models to production history is a very time-consuming process in reservoir modeling. Current practice still involves a tedious historymatching process that is highly subjective and often employs ad-hoc property multipliers. Recently streamline models have shown significant promise in improving the history matching process. In particular, the streamline-based "assisted historymatching" utilizes the streamline trajectories to identify and limit changes only to the regions contributing to the well production history. It is now a well-established procedure and has been applied successfully to numerous field cases.
In this paper, we enhance the streamline-based assisted history matching in two important aspects that can significantly improve its efficiency and effectiveness. First, we utilize streamline-derived analytic sensitivities to determine the spatial distribution and magnitude of the changes needed to improve the history match. Second, we use a "generalized travel time inversion (GTTI)" for model updating via an iterative minimization procedure. Using this approach, we can account for the full coupling of the streamlines rather than changing individual or bundles of streamlines at a time. The approach is more akin to automatic history matching. However, by intervening at every step in the iterative model updating, we can retain control over the process as in assisted history matching. Our approach leads to significant savings in time and manpower during field-scale history matching.
We demonstrate the power of our method using two field examples with model sizes ranging from 105 to 106 grid blocks and with over one hundred wells. The reservoir models include faults, aquifer support and several horizontal/high angle wells. History matching is performed using both assisted history matching and the GTTI. Whereas the general trends in permeability changes are similar for both the methods, the GTTI seems to significantly improve the water cut history matching on a well-by-well basis within a few iterations. Our experience indicates that the GTTI can also be used very effectively to improve the quality of history match derived from the assisted history matching. The changes to the reservoir model from GTTI are found reasonable with no artificial discontinuities or apparent loss of geologic realism.
The Effect of Oil Brine Ratio on Surfactant Adsorption From Microemulsions
Authors: Meyers Kevin O. , Salter Stephen J. 
Published: December 2007

ABSTRACT
Static adsorption measurements of petroleum sulfonates on crushed Bell Creek and Berea cores were made utilizing fluids with the same active surfactant concentration but varying brine-to-oil mass ratios. The salinity of the brine was chosen such that a significant three-phase region existed in the oil/brine/surfactant/alcohol system. The surfactant adsorption was found to be independent of the structural and compositional differences among the fluids.
A series of oil recovery tests in which middle-phase microemulsions were injected into waterflooded cores were also carried out. The cores utilized in these tests had been treated to remove divalent ions accessible to fluid flow. Microemulsion slugs (1.75 to 146 percent pore volume) of equal active surfactant concentration but differing brine-to-oil mass ratios were injected. The total surfactant retention for this system was also found to be independent of the brine-to-oil mass ratio.
Purification of Coal-Bed Methane Produced Water by Zeolite Membranes
Authors: Liangxiong Li , Ryan Ashlee , Nenoff Tina M. , Dong Junhang , Lee Robert 
Published: December 2007

Abstract
This paper reports a new method for purification of coal-bed methane (CBM) produced water by reverse osmosis (RO) through molecular sieve MFI zeolite membranes. The desalination on the zeolite membrane can be thought of as an ion sieving process — the uniform zeolitic pore size (dia. ~0.56nm for MFI) is sufficient for transport of water molecules (dynamic size ~0.29nm) but is small enough to reject hydrated ions and large organic molecules by size exclusion.
In this study, the MFI zeolite membranes were used for desalinating a CBM produced water from Farmington, NM, which contained total dissolved salts (TDS) of ~1.86×104 ppm. The effect of dissolved organics on the desalination efficiency was examined by comparing RO performance for 0.10M KCl solutions with and without dissolved toluene, which was used as a simulator of dissolved organics. The zeolite membrane showed an overall salt rejection of 83.5% for the CBM produced water with organics removed by pretreatment. Experimental results also show that the dissolved toluene affected the ion rejection and water flux only slightly. Due to its extraordinary chemical and structural stabilities, the MFI zeolite membrane may offer an alternative method to treat the organic-containing, high TDS CBM produced water for beneficial use.
Sanding: A Rigorous Examination of the Interplay between Drawdown, Depletion, Start-up Frequency and Water Cut
Authors: Vaziri Hans , Allam Robbie , Kidd Gordon , Bennett Clive , Grose Trevor , Robinson Peter , Malyn Jeremy 
Published: December 2007

Abstract
Factors and mechanisms leading to sanding are described within an integrated rock and soil mechanics framework. While the conventional sanding models generally consider a single-mechanism for sanding, namely the critical depletion resulting in rock disaggregation, the proposed approach considers the inter-play of several mechanisms that can lead to the rock break-up and sand transport. One important difference is that rock disaggregation is not seen to represent the onset of sanding as the sand mass can offer significant resistance due to frictional properties, interlocking of sand grains and arching. The approach presented can be used to explain why sanding in the field tends to be episodic and how depletion, which is a major factor in rock break-up, can be highly effective in holding broken up sand grains together and become a sand stabilization agent.
The proposed approach is used in discussing sanding at several wells in two different fields. These wells have been in production for several years and show that sanding cannot be linked to just one unique mechanism (e.g., depletion). However, once all mechanisms for sanding are incorporated, a more consistent analysis can be used by completion and production engineers to make more objective and pragmatic decisions in managing sanding while maximizing production over the life of the well.
Integrative Interpretation of 3D VSP and Multisource Salt Proximity at Vinton Dome, Louisiana, USA
Authors: Li Yingping , Wang Dapeng , Jackson James 
Published: December 2007

Abstract
This paper presents 3D VSP imaging results of a salt-sediment boundary in the Vinton Dome Field, Louisiana, USA, using both borehole seismic reflection and refraction methods. The SS salt reflections were migrated to generate the salt-sediment boundary image volume and the PP sediment reflected waves were used to produce the depth migration image volume for the complex sediment structures. Multisource 3D salt proximity surveys result in 3D salt exit points which delineate the steep salt-sediment boundary with a significant overhang. 3D VSP Images from two methods are consistence, providing a greater degree of confidence in the interpretation of the complex 3D salt-sediment structures.
A 3D visualization tool especially designed for 3D VSP solutions was used to integrative interpret multi-volumes of 3D VSP images, salt exit points, velocity models, well logs, surface seismic data, and other available data. The use of multifarious VSP imaging techniques and 3D visual tool provides validation of the various results and yields an accurate picture of the salt flank position.
Well Test Analysis of Horizontal wells in Gas-Condensate Reservoirs
Authors: Hashemi Abdolnabi , Nicolas Laurent M. , Gringarten Alain C. 
Published: December 2007

Abstract
Gas condensate reservoirs usually exhibit complex flow behaviors due to the build-up of condensate banks around the wells when the bottomhole pressure drops below the dew point. The formation of this liquid saturation can lead to a severe loss of well productivity and therefore lower gas recovery. Several studies have examined various ways to minimize the pressure drop in order to reduce liquid drop-out and related problems. One solution implemented over the past decade is the use of horizontal wells.
There is a lack of published knowledge on the flow behavior of horizontal wells in gas condensate reservoirs. The limited studies in this area1-3 focused on well performance rather than on well test behavior. There has been no evidence of condensate drop out effects in published horizontal well tests data.
This paper presents preliminary results from a study aimed at establishing an understanding of the near-wellbore well test behavior in horizontal wells in gas condensate reservoirs, with a focus on the existence of different mobility zones due to condensate dropout.
We used a 3D fully compositional model to develop derivative shapes to be expected from horizontal well test data in gas condensate reservoirs below the dew point under various conditions. We then analyzed actual well test data that exhibit such derivative characteristics. Finally, we used a compositional model to verify the results obtained from conventional well test analysis.
It was found that condensate deposit near the wellbore yields a well test composite behavior, similar to what is found in vertical wells, but superimposed on a horizontal well behavior, which makes it much more complex.
Elimination of Biogenic Hydrogen Sulfide in Underground Gas Storage. A Case Study
Authors: Raczkowski Józef , Turkiewicz Anna , Kapusta Piotr 
Published: December 2007

Abstract
The paper reports microbiological study of Sulfate Reducing Bacteria activity in underground gas storage and preventive action against H2S formation. Complex research was performed on natural gas reservoir in Swarzow, where one of a few gas storages in Poland had been arranged. The presence of hydrogen sulfide in the 10-th cycle of UGS exploitation gave impact to search a new effective methods which might limit the microbial processes of sulfate reduction in the reservoir. Having the long-term experience, in 1995-96 operation of biocide treatment in SWARZOW UGS was completed with success. Selective biocides (quaternary ammonium compounds) were applied into the reservoir for the first time in Poland, in accordance with patented technology worked out in Oil and Gas Institute, Department of Microbiology. In 1997-98 the biocide injections to exploitation wells were repeated. These operations conduced to the total elimination of Sulfate Reducing Bacteria from the formation waters and caused partial reduction of H2S content in natural gas recovered from the reservoir. In 2003 the new technology based on synergetic action of biocide, represented by triazine derivatives, and H2S Scavenger (Sulfa Clear) was implemented for the first time in underground environment. Practical application of this technology on 2 objects of UGS was finished with a great success. Content of hydrogen sulfide in the recovered gas and formation waters now accords with European Standards. The paper also discusses microbiological studies of processes observed in the natural gas reservoir in Wierzchowice, which is the largest store in Poland. Its final capacity will be ca. 4,3 billion cubic meters of natural gas. The research was conducted between the 1st and the 8th cycle of UGS exploitation. Present investigations were performed in the monitoring system and included microbiological and chemical analysis of formation waters and drilling fluids. Active strains of H2S producing bacteria (Desulfovibrio sp. and Desulfotomaculum sp.) isolated from the reservoir, have been used for testing biocides selected to protect exploitation wells of WIERZCHOWICE UGS.
Streamline-Based Production Data Integration in Naturally Fractured Reservoirs
Authors: Al-Harbi Mishal , Cheng Hao , He Zhong , Datta-Gupta Akhil 
Published: December 2007

AbstractStreamline-based models have shown great potential in reconciling high resolution geologic models to production data. In this paper we extend the streamline-based production data integration technique to naturally fractured reservoirs. Describing fluid transport in fractured reservoirs poses additional challenge arising from the matrix-fracture interactions. We use a dual-porosity streamline model for fracture flow simulation by treating the fracture and matrix as separate continua that are connected through a transfer function. Next, we analytically compute the sensitivities that define the relationship between the reservoir properties and the production response in fractured reservoirs. The sensitivities are an integral part of our approach and can be evaluated very efficiently as 1-D integrals along streamlines. Finally, the production data integration is carried out via a generalized travel time inversion which has been shown to be robust because of its quasi-linear properties and utilizes established techniques from geophysical inverse theory.We also apply the streamline-derived sensitivities in conjunction with a dual porosity finite difference simulator to combine the efficiency of the streamline approach with the versatility of the finite difference approach. This significantly broadens the applicability of the streamline-based approach in terms of incorporating compressibility effects and complex physics. We demonstrate the power and utility of our approach using 2-D and 3-D synthetic examples designed after actual field conditions. The reference fracture patterns are generated using a discrete fracture network (DFN) model that allows us to include statistical properties of fracture swarms, fracture densities and network geometries. The DFN is then converted to a continuum model with equivalent grid block permeabilities. Starting with prior models with varying degrees of fracture information, we match the water-cut history from the reference model. Both dual porosity streamline and finite difference simulators are used to model fluid flow in the fractured media. Our results indicate the effectiveness of our approach and the role of prior information and production data in reproducing fracture connectivities and preferential flow paths.
Is Side-Cutting Really Necessary for Steerable Bits?
Authors: Gaynor Tom , Chen David C-K 
Published: December 2007

Abstract
PDC bits with aggressive gauge designs are often considered to have a higher side-cutting capability and thus are frequently used in directional drilling systems to increase the build rate. However, aggressive bits are prone to bit whirl and hole spiraling, resulting in bit and BHA/MWD failures and poor hole quality. Long-gauge bits are known to reduce bit vibration and produce high quality wellbores. The question is then "can long-gauge bits — which by their nature do not side-cut — be used to drill directional wells?" To solve this puzzle, Halliburton Sperry-Sun has been studying the use of long-gauge bits with steerable motors and rotary steerable systems. The results show that BHA steerability is mostly determined by the dog-leg capability of the BHA and the ease of setting the tool face. The side-cutting capability of the bit can be decoupled from BHA steerability. Therefore, side cutting capability is not necessary for steerable bits when run with an appropriate BHA.
Analytical Method of Evaluating Productivity Index for Constant Production Rate or Constant Wellbore Pressure
Authors: Ibragimov A. , Khalmanova D. , Valko P. P. , Walton J. 
Published: December 2007

AbstractThe existing methods for evaluating the well productivity index are based on solution of transient problems. One approach is to consider the single well problem in infinite domain and subsequently apply the method of images. This puts restrictions on the geometry of the well and of the drainage volume. Another approach is to solve the transient problem in the bounded domain for late times. While in this case restrictions on the well geometry are less severe, the shape of the drainage volume is still limited to the simplest ones. In addition, for the constant rate case highly accurate wellbore pressures, for the constant pressure case highly accurate wellbore rates are required and that puts an extreme computational burden on the semi-analytical or numerical methods involved. Even with the most powerful methods and hardware available, the calculation of the productivity index of directionally drilled and partially penetrating wells, especially in more complex drainage volumes is a formidable task.An additional problem is that in general, the productivity index for a well produced under constant pressure condition is different, although very close, from the productivity index of a well produced with constant rate.In this work we present a new technique to evaluate single well productivity indices both for constant pressure and for constant rate conditions. The approach is based on the solution of two steady state boundary value problems with constant pressure prescribed on the wellbore. The two productivity indices, (for constant rate and constant wellbore pressure, respectively) are then computed as integral characteristics of the solutions of the corresponding time dependent boundary value problem. The two productivity indices are computed independently.The method can be applied to any geometry of the reservoir (both 2-D and 3-D, regular or irregular), and any direction and length of penetration of the well. Designer wells (with a freely prescribed path) can be also considered.
Generating Multiple History-Matched Reservoir Model Realizations Using Wavelets
Authors: Sahni Isha , Horne Roland N. 
Published: December 2007

Abstract
This paper focuses on an automated way to generate multiple history-matched reservoir models with the inclusion of both geological uncertainty and varying levels of trust in the production data, using wavelet methods. As opposed to previously developed automated history-matching algorithms, this methodology not only ensures geological consistency in the final models, but also includes uncertainty in the production data.
A data distribution, say a permeability field, can be (reversibly) transformed into wavelet space where it fully described by a set of wavelet coefficients. It was found that different subsets of the collection of wavelet coefficients can be constrained separately to: (a) the production history, and (b) the geological constraints. This means the history match need only be performed once, after which multiple realizations can be generated by adjusting just the second subset of coefficients.
The ability to include both geological and production data uncertainty into reservoir model automatically is of great consequence to reservoir modeling and hence to reservoir management, risk analysis and making key economic decisions. The more complete and realistic reservoir model will lead to better reservoir production and development decisions.
Identification of Payzones from Log Measurements in Casing in Difficult Drilling Environment
Authors: Endisha Abdurrazag , El Mahdy Reda , Guru Udit Kumar 
Published: December 2007

Abstract
Open hole log evaluation has been traditionally used for formation evaluation purposes and is commonly used for reservoir characterization. Adverse hole conditions precluded use of these services. Under these circumstances, it becomes necessary to acquire the necessary log data after the well is cased for reservoir evaluation.
Cased hole logs provide answers with acceptable uncertainty in characterized formations. However, in cased wells, which are not well characterized, the results tend to have a higher uncertainty.
In one of the wells in Egypt the operator could not acquire the data in the open hole section because of adverse hole conditions. High quality cased hole data was acquired in the interesting section even in difficult borehole condition (heavy wash outs etc). The measurements are compared with the available open hole data and the responses explained. All the data which could have been acquired in the open hole was acquired in the cased hole with the available cased hole sensors. . Based on the data from the cased hole the bore hole condition at the time of casing the well was predicted. .
We also demonstrate that gaseous hydrocarbon can be identified from the cased hole epithermal neutron measurements which compared well with the resistivity and the density neutron separation. Reliable matrix density values have been estimated from the cased hole spectroscopy providing a reliable porosity values from the cased hole density
Reservoir parameters have been estimated in the cased hole section. It was possible to devise cost effective planning for completing the well based on these parameters.
The ability to provide cased hole measurements helped the operator in avoiding a costly side track. .