bluuebunny/crossref_metadata_2025 huggingface dataset:
Pressure Transient Analysis for a Stratified Water-Dissolved and Mud-Adsorbed Gas Formation
Authors: Arihara Norio , Nakamura Keigo , Abbaszadeh Maghsood , Tamura Kazuhiro
Published: December 2007

This paper studies pressure transient behavior in a water-dissolved and mud-adsorbed gas reservoir, from which gas is co-produced with water saturating stratified sandstone and mudstone laminae of a high permeability contrast. There are horizontal flow into wellbore from the permeable sand layers and vertical crossflow in reservoir from mudstone laminae into sand zones because of extremely low permeability of mud layers. When reservoir pressure declines, dissolved gas in brine is liberated from both the sand and mud layers, and two-phase flow occurs towards production wells. In addition to dissolved gas, adsorbed gas on mud particle surfaces is also liberated as reservoir pressure decreased.

A new model is formulated for two-phase gas and water flow in a multilayer system including gas desorption effects and crossflow in the formation. Gas desorption is modeled by Langmuir isotherm with instantaneous diffusion. New type curves are provided in terms of total phase mobility-thickness ratio K, storativity ratio, and two-phase crossflow parameter. The effect of gas desorption is accounted for by through equivalent total compressibility. Distinct features of type curves are illustrated for pseudo-steady state and transient inter-layer crossflow. An actual well test is analyzed by the present model to yield the layer properties of strong contrast.

P. 65
Field Implementation of Geological Steering Techniques Optimizes Drilling in Highly-Deviated and Horizontal Wells
Authors: Jackson Charles E. , Illfelder Herbert M. J. , Pineda Giser
Published: December 2007

In geological steering, the well path's position is monitored by comparing logs obtained while drilling to logs predicted from a geological model prepared before drilling. Often, important petrophysical evaluation of the logged data needed to refine the geological model is done offsite, delaying full use of the resulting model until subsequent wells are drilled. Furthermore, conclusions drawn from comparisons of logged and predicted data are often presented in geological and logging terms, and are not always explained in clearly defined drilling objectives.

This paper describes a field implementation of an integrated wellsite geological steering service. The service provides timely, useful feedback from real-time logging-while-drilling (LWD) measurements for making immediate course corrections. This service's real-time aspect and its capability to furnish information easily understandable to the geologist, LWD analyst, and driller alike help optimize drilling to the target zone. Visualization is key to this understanding and is provided through interactive multidimensional displays of both the geological and petrophysical properties of formations being penetrated by the wellbore.

This service's true value is realized through incorporation of unique well-planning utilities that automatically incorporate the logged and predicted data and the geological model to help accurately guide the well. As an ancillary benefit, the same computational engine used by the steering service can be employed to sharpen the petrophysical analysis of the logged data used for formation evaluation. This paper briefly reviews forward modeling techniques and describes fundamental principles underlying the new application. Examples illustrate the application of the new service.
Horizontal Well Technology in the Oilfield of China
Authors: Xiange Liu , Shangqi Liu , Zhixiang Jiang
Published: December 2007

This paper describes the basic status of horizontal well development and recovery technology in the onshore oilfield of China, that including the technology developed from the bottom-water reservoirs (light oil), heavy oil reservoirs with thermal recovery, low permeability reservoirs and high water cut water flooding reservoirs, and approaching the problems existed in the further development.
Examination of Seismic Repeatability as a Key Element of Time-Lapse Seismic Monitoring
Authors: Hughes John K.
Published: December 2007

The propagation of elastic waves in rocks is determined by the bulk modulus, shear modulus and bulk density of the rock. In porous rocks all these properties are affected by the distribution of pore space, the geometry and inter-connectivity of the pores, and the nature of the fluid occupying the pore space. In addition, the bulk and shear moduli are also affected by the effective pressure, equivalent to the difference between the confining (or lithostatic) pressure and pore pressure.

During production of hydrocarbons from a reservoir, the movement of fluids and changes in pore pressure may contribute to a significant change in the elastic moduli and bulk density of the reservoir rocks. This phenomenon is the basis for reservoir monitoring by repeated seismic (or time- lapse) surveys whereby the difference in seismic response during the lifetime of the field can be directly related to changes in the pore fluids and/or pore pressure. Under suitable conditions, these changes in the reservoir during production can be quantitatively estimated by appropriate repeat 3D seismic surveys which can contribute to the understanding of the reservoir model away from the wells. The benefit to reservoir management is a better flow model which incorporates the information derived from the seismic data.

What are suitable conditions? There are two primary factors which determine whether the reservoir changes we wish to observe will be detectable in the seismic data:

The magnitude of the change in the elastic moduli (and bulk density) of the reservoir rocks as a result of fluid displacement, pressure changes etc. The magnitude of the repeatability errors between time- lapse seismic surveys. This includes errors associated with seismic data collection, ambient noise and data processing.

The first is the signal component and the second the noise component. Previous reviews of seismic monitoring suggest that for 3D seismic surveys, a signal-to-noise ratio of 1.0 is sufficient for qualitative estimation of reservoir changes. Higher S/N ratios may allow quantitative estimates.

After a brief examination of the rock physics affecting the seismic signal, we examine the second factor, repeatability errors, and use a synthetic seismic model to illustrate some of the factors which contribute to repeatability error. We also use two land 3D surveys over a Middle East carbonate reservoir to illustrate seismic repeatabilty. The study finds that repeatability errors, while always larger than desired, are generally within limits which will allow production-induced changes in seismic reflectivity be confidently detected.

P. 519
Unique Test Process Resolves Junction Difficulties in a Multilateral Completion on the North Sea Statfjord Field
Authors: Hovda Sigve , Arrestad Arild , Bjorneli Hans Magnus , Freeman Austin
Published: December 2007

The Statfjord Field is the largest producing oilfield in the North Sea. To date, 159 wells have been drilled, 35 of which have been sidetracks. To increase the recoverable reserves for the remaining slots, it was felt that multilateral completions would provide the best option since the targeted reservoirs were small, and thus, would have to be combined to provide economic feasibility. The multilateral concept is comparatively new, and as with all pioneering technology, each field experience can present scenarios that have not previously been addressed.

This paper will discuss a problem that occurred during installation of well C-23. In this case, difficulties in cementing the area around the junction occurred. During later drawdowns, the junction partially collapsed, preventing fullbore access to the parent well bore.

After the problems were noted, a unique testing process was developed and used to determine the circumstances that had caused the junction failure. Since the integrity of the multilateral concept is dependent upon the efficiency of the junction area, the test process was also used to provide a comparison of the strength ratios of supported and unsupported junctions and to observe lateral liner loading.

The testing process succeeded in determining the cause of the C-23 problem and identified general requirements critical for maintaining integrity in the type of multilateral completion being used in the Statfjord Field. Since Statoil was planning two additional multilateral wells, it was particularly important to determine the reason for the C-23 difficulties so that a failure of this nature would be prevented in future wells.

P. 265
The Most Significant Application of Horizontal Wells in Eastern Europe
Authors: Kristof Peter , Vukov Ivan , Kecskes Tamas , Ordogh Balazs
Published: December 2007

The presentation deals with the most important application of horizontal wells in Hungary, and as well - as we know - the most important application in Central- & Eastern Europe. The presented data refer to the production aspect of using horizontal wells and represent real data. The reason - of course - why we use horizontal wells, is to increase the production rate and the final rate of recovery. But, we use this technology in three total different reservoir.

The first one is the AP-1 3 reservoir, which has a very low permeability and high anisotropy. Obtaining the required production per well is possible only using horizontal wells.

The second area the application of horizontal wells is the reduction of gas coning in reservoir CsD-2. This reservoir is a very thin oil layer with big gas cap. The optimal production rate, GOR and GLR during production is possible to maintain only using horizontal wells.

The third field of the application of horizontal wells is to produce oil form the untouched zones of reservoir A-2. The most economical solution for oil production from these zones was the using horizontal wells.

Furthermore, there are applications of horizontal wells in Algyo field as gas producer and water injector wells. Data related to these two areas are briefly mentioned in the article.

The presentation does not deal with the exploitation, the drilling and completion of the wells, or other aspects of horizontal wells. The only one field touched in the presentation is production. We compare and analyze the production data of horizontal wells versus vertical wells, and we point in the horizontal wells advantages in production.

P. 417
Studies on the Prevention of Gas Hydrates Formation in Pipelines Using Potassium Formate as a Thermodynamic Inhibitor
Authors: Fadnes F.H. , Jakobsen T. , Bylov M. , Holst A. , Downs J.D.
Published: December 2007

Large volumes of methanol and glycol are routinely injected into gas transport pipelines to inhibit the formation of gas hydrates. Preliminary studies have indicated that potassium formate could be a more effective thermodynamic gas hydrate inhibitor for use in certain gas transport operations. Potassium lormate is a benign and environmentally-acceptable organic salt which is widely used in the oif fleld industry as a component of drilling and completion fluids. The influence of potassium formate on gas hydrate equilibria has been described in a thermodynamic model which closely fits experimental data generated in a high pressure PVT cell. Economic evaluations suggest that potassium formate is best suited for gas hydrate inhibition applications where inhibitor recovery and regeneration are practised, and where contamination of both the transported hydrocarbon and the local environment must be minimised.

P. 497
Modification of Oil and Water Permeabilities in Berea Sandstone by a Gel Treatment
Authors: Yan Z. , McCool C.S. , Green D.W. , Willhite G.P.
Published: December 2007

This paper was prepared for presentation at the 1999 SPE International Symposium on Oilfield Chemistry held in Houston, Texas, 16-19 February 1999.
A Systematic Study of Iron Control Chemicals - Part 2
Authors: Taylor K.C. , Nasr-El-Din H.A.
Published: December 2007

This paper was prepared for presentation at the 1999 SPE International Symposium on Oilfield Chemistry held in Houston, Texas, 16-19 February 1999.
Modern Technique, Complete Sets, High Quality and High Speed Drilling Applied in Bohai
Authors: Wei Jiang
Published: December 2007

This paper mainly describes the application of ten advanced drilling techniques, by Bohai Corporation when doing its high quality and high speed drilling operations, such as PDC bit, guided motor drilling, PDC drillable float collar and shoe, slam-combination, MWD, top-drive drilling, compact well head, non-waiting time for cementing and linear shaleshaker etc.

The application of such techniques have not only played an active impetus role in enhancing drilling speed and ensuring field construction and development in Bohai, but also gradually established and completed a number of scientific and strict standards and control systems for quality evaluation and acceptance. More importantly, it helps change the ideology of the people and enhance management level and technical quality. Scientific progress and change of people's ideology, it will bring about great impact in Bohai oil field development and construction.
Development and Application of Horizontal Drilling Technology Onland in China
Authors: Wang Guanging , Su Yinao , Zhou Yuhui
Published: December 2007

This paper gives an introduction to the technical development and applications of horizontal drilling technologies on land in China since 1990's. It illustrates the distribution of the well locations, the characteristics of hydrocarbon reservoirs, the technical research achievements, the technical capabilities, the completion methods, the economic appraisals, the newly developed tools and instruments for the 160 horizontal wells drilled by CNPC(China National Petroleum Corporation). Some typical application of horizontal wells is also available.

P. 213
Effective Development of a Low PermeabilityReservoir Achieved: A Case Study
Authors: Li Xingxun , Wang Zhengde , Du Wenjun , Shen Nan , Yin Dongying
Published: December 2007

Through constantly deepening the understanding of the reservoirs and adopting effective measures of adjustment and control, the low permeability heterogeneous reservoirs, Xishanyao reservoirs of Cainan oilfield, have been developed for four years in succession at the rate above 2.5% while maintaining the water-cut increasing rate under 3.5%. It means that the development of the reservoirs of the has reached a high level in Cainan oil field.

P. 351
Completion Technique of Sidetracked Horizontal Well
Authors: Cai Qingjun , Zhou Zhiqi , Wang Zenglin , Hu Fengtao , Li Leixiang
Published: December 2007

In order to raise the recovery ratio of maturing field, Shengli Petroleum Administration has carried out a project of sidetracking horizontal wells in existing straight wells from the latter of 1995. This paper will introduce the completion technique used to sidetrack horizontal wells within 5 1/2in casing including geologic condition, reservoir type, selection and design of completion type, researches and design of completion tubing along with downhole tools and wellbore treatment etc.. In addition, the question of reservoir protection is discussed, and a few conclusions were made.

P. 399
Main Problems in Developing Low Permeability Reservoir and Its Improvement Ways
Authors: Li Daopin
Published: December 2007

It is very difficult to develop the low permeability reservoir. Nowadays it faces serious challenging because of the decline of oil price. In the paper, based on a great amount of investigation, the main problems in developing low permeability reservoir with water flooding are pointed out and the main causes to form these problems are analyzed. According to the theoretical study and practical experiences, the main ways to develop the low permeability reservoir efficiently and economically are given. It is to raise the oil production, recovery rate and recovery factor on the basis of scientific and rational development plan on the one hand; to improve the process technology and reduce the investment and cost on the other hand. As a result, the better development results and economic benefit can be obtained in developing low permeability reservoirs.

P. 403
Successful Use of a Strategic Alliance for a Major Gas-Storage Project
Authors: Daniel Steve , Rubin Bill , Kozera Greg
Published: December 2007

Before 1996, Columbia Gas Transmission was concerned about inefficiency in its business practices. In addition, the Market Expansion Project, a 3-year project that would double Columbia's deliverability to help meet market demands, was scheduled to begin in 1997. These situations prompted Columbia to consider forming a strategic alliance with several service companies to more efficiently accomplish its goals. In March 1996, Baroid Drilling (mud services), Halliburton Energy Services, Inc. (pumping services), WellTech Eastern, Inc. (rig services), Baker Atlas Logging Services (logging services), and Columbia Gas Transmission (storage services) joined to form the Columbia Appala-chian Storage Alliance (CASA). Since that time, the Alliance has been responsible for all of Columbia's well-storage work. This paper will discuss what prompted Columbia to seek an alliance, the processes involved in developing and structuring the alliance and choosing members, and the problems and successes encountered during the first 2 years of the alliance.
Inexact Newton-Krylov Methods for the Solution of Implicit Reservoir Simulation Problems
Authors: Kim Jong Gyun , Deo Milind D.
Published: December 2007

For the solution of nonlinear equations resulting due to the implicit discretization of reservoir simulation partial differential equations, Newton's method has been an overwhelming choice. By providing robust and a considerably faster performance, the inexact Newton's methods offer attractive alternatives. Several Newton-Krylov inexact methods were examined for the solution of nonlinear equations arising in the finite-element discretization of a discrete-fracture reservoir simulation model. Two of the methods were found to be superior to the Newton's method. These techniques also had the additional advantage of being amenable to effective parallelization.
A Simple Method for Handling Irregular Boundaries in Reservoir Simulation
Authors: Carlson E. S. , Vora V. V.
Published: December 2007

In this paper, we summarize a methodology based on multidimensional finite differencing (MDFD) for the numerical solution of partial differential equations. Although the general methodology is not new, we present some original modifications that use Cartesian-based gridding. In theory, this methodology is applicable for any type of boundary conditions, linear or nonlinear, steady state or unsteady state. The two most important characteristics of the methodology are the simplicity of the formulation and the fact that no distortion or refinement of the Cartesian grid is necessary to accommodate a non-Cartesian (irregular) boundary. For example cases, Neumann and Dirichlet conditions are applied in the numerical solution of the unsteady-state heat-conduction equation.

This paper has three primary benefits. First, we provide a classification system for MDFD methods. Second, we present a new MDFD method involving the combination of interpolation through nodes and regression through boundary conditions. Finally, we present cases where MDFD fails to provide an acceptable result, and other cases where super accuracy occurs.
A Comparison of Two-Phase Inflow Performance Relationships
Authors: Gallice Frederic , Wiggins Michael L.
Published: December 2007

Petroleum engineers are routinely required to predict the pressure-production behavior of individual oil wells. These estimates of well performance assist the engineer in evaluating various operating conditions, determining the optimum production scheme, and designing production equipment and artificial lift systems.

In this paper, commonly used empirical inflow performance relationships for estimating the pressure-production behavior during two-phase flow are investigated. Relationships studied include those proposed by Vogel, Fetkovich, Jones, Blount and Glaze, Klins and Majcher, and Sukarno. Each method will be briefly described and methods used to develop the relationship will be discussed.

Based on actual vertical well data, the relationships are used to predict performance for twenty-six cases. The predicted performance is then compared to actual measured rate and pressure data. The variation between the predicted and measured data are analyzed. From this analysis, recommendations are made on the use of inflow performance relationships to predict performance, collection of data, and the quality of performance estimates.
Hardbanding and Its Role in Directional/Horizontal Drilling
Authors: Mobley John G.
Published: December 2007

Hardbanding of drill pipe tool joints and other drilling equipment has been around since the late 1930's. Originally, hardbanding was applied primarily to protect the drill pipe and other tools from premature abrasive wear. Since that time, there have been numerous changes in hardbanding and its application, but only within the last few years has new technology been introduced that allows hardbanding to protect the casing and the drill pipe at the same time.

Hardbanding is one of the most simple yet most misunderstood products being used on a drilling rig today. Along with the new technology being utilized to drill the highly deviated wells, such as horizontal, ERD, or multi directional, comes the problem of creating excessive downhole drag and torque. All of this drag and torque creates friction, which, in turn, creates wear on the drill string and the casing. Today, there are several types of wear resistant alloy hardbandings on the market. Most of them are designed to protect either the casing or the drill string, but only one or two of them can sufficiently protect both of them at the same time.

Though the wear resistant alloy hardbanding technology has only been on the market for 6-8 years, it has gained increased popularity over conventional tungsten carbide hardbanding for several reasons. This technical paper will attempt to address these points in order to educate concerned parties as to which hardbanding to use in a particular situation.

The proper hardbanding with the right application can:

▪ Substantially increase the tool joint wear life ▪ Greatly reduce casing wear caused by the drill string ▪ Substantially reduce downhole drag and torque ▪ Reduce rig fuel consumption ▪ Allow operators to run lighter weight and grade casing
Deepwater Sampling at a Synthetic Drilling Mud Discharge Site on the Outer Continental Shelf, Northern Gulf of Mexico
Authors: Fechhelm R. G. , Gallaway B. J. , Farmer J. M.
Published: December 2007

Between 1992 and 1994, BP Exploration drilled ten wells from a single jacket at a depth of 393 meters in MMS Lease Block Viosca Knoll 989 (Pompano Phase I). Production began in October 1994. The second phase, utilizing a subsea template, was drilled between 1995 and 1997 at a depth of 565 meters in Mississippi Canyon Block 28, four miles downslope (Pompano Phase II). Both water based muds and synthetic muds were used. An additional well was drilled at Mississippi Canyon 28 in early 1998. This review describes the procedures used to survey the deepwater seafloor in July 1997 and March 1998 using a remote operated vehicle (ROV). Included are qualitative and quantitative sampling of the bottom sediment for chemical and benthic analyses using core samplers and videotransects for identification and enumeration of fish and large invertebrates.

The goals of this project were to document: the size and extent of the cuttings piles following two+ years of a multi-well development drilling program in the deep Gulf; the con-centrations of synthetic based drilling fluids (SBFs) in sediments around the drilling template; and the appearance of the bottom sediments with respect to chemical activity and densities of macrofauna and megafauna at the same locations. The main purposes of the follow-up study were to compare findings with those seen earlier and to identify changes in the structure of the local macrofauna and megafauna biological communities since the July 1997 survey. Results of both the 1997 and 1998 studies were compared to data collected at similar depths in the eastern and western Gulf during the MMS baseline studies conducted in the 1980s.
Well Construction in Azerbaijan (Onshore)
Authors: Guild G.J. , Retondo C.D. , Corbaci M. , Manafov S.
Published: December 2007

This paper was prepared for presentation at the 1999 SPE/IADC Drilling Conference held in Amsterdam, Holland, 9-11 March 1999.
Determining the Risk in Applying Multilateral Technology: Gaining a Better Understanding
Authors: Waddell Kevin K.
Published: December 2007

Traditionally, operators have reviewed experience from other job scenarios to assess feasibility when considering application of a technology. Therefore, when data concerning field usage is limited, as is the case for emerging technologies, new concepts that show promise of providing significant economic benefit are oftened abandoned. Generally, this is because of misconceptions concerning the associated risks of its usage. Since the assessment of the benefits of new technology cannot be based upon previous experience, an accurate method for understanding the "unknowns" of a new technique and analyzing the probable economic ramifications has been needed.

This paper will present a methodology that has been developed to overcome the assessment difficulties that accompany the use of new technology. This analytical process will attempt to quantify risk factors and determine event probabilities in the application of an emerging technology so that the unknowns previously supplied by experience can be predetermined in the application of new concepts. The process, its analytical concepts, and the model development that has been designed to assist operating companies in determining field applications for one of the new completion concept in the oilfield — multilateral technology — will be presented.

The analytical system discussed in this paper considers the difficulties in risk analysis for an emerging technology and uses the established techniques of "Quantitative Risk and Decision Tree" analysis and Monte Carlo / Latin Hypercube analytical simulation to correlate information that has been developed by operational and experience databases. The system facilitates the benchmarking of associated risk-weighted cost of system installation, determines "cutoff" points, and evaluates probable outcome impacts on the net present value (NPV) of a project.

Included in the paper are several examples and one case history. The information will provide a technique that will help answer questions raised in the process of risk assessment, not only for the specific area of multilateral technology to which it has been applied, but for other concepts as well.
Measuring the Impact of 3-D Seismic on Business Performance
Authors: Aylor William K.
Published: December 2007

This paper was prepared for presentation at the 1999 SPE Hydrocarbon Economics and Evaluation Symposium held in Dallas, Texas, 20-23 March 1999.
The Cost-of-Capital and Fair Market Value Discount Rates
Authors: Miller Richard J.
Published: December 2007

This paper was prepared for presentation at the 1999 SPE Hydrocarbon Economics and Evaluation Symposium held in Dallas, Texas, 20-23 March 1999.
Effect of Non-Uniform Formation Damage on the Inflow Performance of Horizontal Wells.
Authors: Menouar Habib , Al-Majed Abdulaziz , Hasan Syed Sajid
Published: December 2007

This paper was prepared for presentation at the 1999 SPE Middle East Oil Show held in Bahrain, 20-23 February 1999.
Cementing through High Pressure Coiled Tubing on HPHT Khuff Gas Well Offshore Abu Dhabi
Authors: Mazen A. , Rouatbi R. , Zaki S.
Published: December 2007

Multizone selective production testing of a gas well is a time consuming and costly operation. A Khuff formation is a High Pressure High Temperature (HPHT) and high flow rate gas reservoir with the presence of H2S and CO2. Traditionally, the multizone zone selective production testing operations for Khuff gas wells were performed using conventional methods. The use of Coiled Tubing (CT) on Khuff gas wells was limited only to displacing wells to diesel prior perforating the Khuff reservoir.

This paper describes ADMA-OPCO experience to utilize a High Pressure Coiled Tubing (HPCT) package for the first time in Abu Dhabi and Offshore the Arabian Gulf to perform the different operations involved in the multizone selective production testing of a gas well with the objectives of safely reducing the operating time and costs.
Gas Conservation and Flaring Minimisation
Authors: Tarmoom Ihab Othman
Published: December 2007

Environmental issues have always been important in the oil and gas sectors and it has become more essential for this industry to control and minimize the undesirable emissions and discharges into the atmosphere. Abu Dhabi National Oil Company (ADNOC) has adopted new environmental guidelines to be followed by all the oil and gas affiliate companies in Abu Dhabi and in particular launched a strong campaign to conserve gas usage and minimize flaring with an ambitious objective of zero flaring.

ADNOC established a task force comprising representatives from all Abu Dhabi oil & gas companies in both upstream and downstream sectors of the industry to define, review and study gas flaring and gas conservation.

International consultants from all over the world were invited to participate in reviewing the companies facilities to cover the scope set by ADNOC which covers but not limited to the following study areas.

Recover and utilize the continuously flared gases Conserve and Rationalize gas usage. Identify areas were zero flaring could be achieved whilst maintaining the integrity, safety and reliability of the system.

This paper shall cover the outcome of the studies that were recently conducted. It addresses results that have been achieved to date, the areas where potential gas conservation and reduction of gas flaring have been identified. In addition, it will touch on the ambitious future ADNOC plans for achieving zero flaring.
Water and Gas Tracers at El Furrial Field
Authors: Vilela M. A. , Zerpa L. B. , Mengual R.
Published: December 2007

El Furrial field is an anticline structure that has been exploded since 1986. In order to keep pressure, a water injection program by the flanks of the reservoir was started in 1992. In 1995 four different radioactive tracers were injected through 14 wells, aiming at getting a correlation between producing well and injectors. In this paper the result of the water tracer program developed at El Furrial field is discussed; 14 tracers breakthrough at the producing wells, one of them in November 1996 and the others during 1997 and 1998.

Previous reservoir and geological studies were conducted determining the connection between wells and sands. With the tracer responses we have got new ideas about the correlation among wells, e.g. sealing faults, channeling between producing wells and injectors, barriers, etc. In this paper we match both results.

Additionally, in 1998 a gas injection program was started at the crest of the field. Together with gas injection, a gas tracer program was planed to be carrying out. Here, is presented the design of gas tracer injection for the 5 gas injecting wells.
How to Improve E&P Knowledge through Competency Model Development and Self-Learning Processes
Authors: Brandt R. , Vargas de Alamo N. , Rondón L. , García A.
Published: December 2007

This article summarizes the efforts made by the Production Business Unit of Petroleos de Venezuela, PDVSA-Producción, in the area of Competencies, with the aim of optimizing its levels of excellency in a globalized market each time more competitive and presenting price scenarios that are scarcely favorable.

In this regard, the strategic orientation established by the corporation is defined, indicating, as a fundamental element, the creation of the Competency Development and Maintenance Management – DMC. DMC's mission is to guarantee highly skilled personnel with the critical competencies required for complying on time the objectives of the Business Plan. Its vision is that of positioning PDVSA Production as a leading company in the development and maintenance of its personnel's competencies, while integrating the process of competency development into the processes of the business.

Concrete actions were taken by DMC in the areas of Recruiting and Training personnel, highlighting the design of a Competency Measurement tool – SADINAP -, as a fundamental support for handling managerial information.

The second part of the article refers to Virtual Technology as an element that facilitates the design and implementation of a virtual system of distance education – VLS – whose pilot phase is currently being developed. There is also particular emphasis on the role played in this project by the Communities of Knowledge through specialists who are considered as critical factors of success.

Lastly are mentioned the aspects related to a Program of Sustainable Self-development. This Program translates DMC's actions – oriented towards propelling the behavior in the organization in terms of acceptance or rejection – into the implementation of new training technologies or modalities, aiming to take on time actions oriented towards definitively establishing a self-development culture in the organization.
Sand Control in Open Hole Horizontal Wells-Case Histories and Developments
Authors: Rovina Paulo S. , Filho Everaldo Lima
Published: December 2007

The discovery of new fields in the Amazon forest and in deep water offshore Campos Basin, all of them consisted of unconsolidated sand, led Petrobras to adopt non conventional wells and sand control techniques. The main goals were to increase productivity, delay gas/water conning and support unconsolidated formations in water injection wells.

The first horizontal well was completed in December 94 in Rio Urucu field. Since there was only one zone to drain the barefoot completion was suitable to all fields.

This paper will describe the experience acquired running screens in 28 horizontal open hole wells in Brazil. Among them 19 have been producing oil and 1 injecting water. The other 8 haven't been connected yet to platforms so only results of production (or injection) tests will be reported.

Several improvements were made on the equipment, drilling fluid, procedures and in the well design due to the problems faced during the execution of the jobs.

As a result, the main objectives were achieved and new trends were established aimed at deep water fields development.

Recently, some horizontal wells have been gravel packed and better productivity indexes were reached. The main issues and results for those gravel packings (three jobs so far) will be mentioned.
A Fiber-Optic Inspection System for Prepacked Screens
Authors: Hamid Syed , Lester G. Scott , Adkins Darrell W.
Published: December 2007

Screens are one of the most critical components of a well completion. A screen failure is generally serious, requiring a workover, a sidetrack, or, in the worst case, abandonment of the well. Prepacked screens are used extensively in well completions primarily where there is an increased concern for sand control reliability. These screens have performed successfully in the industry with a few exceptions. One of the reasons for the varying degrees of performance is the difficulty in the inspection of this type of screen.

Performance of a prepacked screen depends on pack thickness and pack tightness (or density). The local pack thickness is dictated by the concentricity of the inner and outer jackets of the screen. Eccentricity between the inner and outer jackets leads to thin packs (on one side) resulting in high, localized fluid velocities, which tend to promote erosion of the screen. It is difficult to nondestructively measure the pack thickness and tightness. As a result, the screen must be inspected by the conventional method by shining light from inside and visually inspecting for defects. At best, this is a qualitative method that is inherently operator-dependent. To overcome these difficulties, a fiber-optics-based system has been designed and tested to inspect the prepacked screens. A mathematical model has also been developed to predict the passage of light through a pack of gravel.

Due to the availability of this inspection system, several modifications have been made in the screen manufacturing process that achieve previously unattainable concentricity and pack tightness. A large number (i.e., 550) of screens have been tested using this technique with excellent results. The different pack thicknesses and gravel sizes can be easily discerned with this inspection technique, which leads to a better quality product.
Use of the Combined Resistivity and Acoustic Image Logs in Designing Patterns of Injection and Producing Wells in a Waterflooding Project
Authors: Saavedra Benito , Basso Alejandro Lopez , Yarke Carlos , Breda Eduardo , D'Angiola Marta
Published: December 2007

This paper describes important structural and sedimentological conclusions obtained with the use of the combined images log (resistivity and acoustic) STAR which was run in the well LP -1404 of Los Perales - Las Mesetas field (San Jorge Basin-Argentina), and their application in the design of the pattern of injector and producer wells in a waterflooding project currently being implemented. A detail of those conclusions is the following: It was confirmed, with the study of the breakout in the acoustic image, the previous hypothesis that it was a structural scheme of tectonic inversion.The statistical study of the open and closed fractures identified mainly by the combination of the images produced by the transit time and the amplitude of acoustic wave, led to obtain the direction and angles of the identified fractures.The statistical study of the strata planes identified in both images let to obtain the angle and trend of the layers by structural effect, being possible then, to define the directions of sedimentation of the psamítics bodies that compose the reservoirs of the field, making the subtraction of the structural dip to those that belong to those sandstone levels.

The definitions of the main directions of the sand bodies that compose the reservoirs of the studied area and, with the breakout study, the directions of the current maximum and minimum stress of the block that belong the well LP - 1404 allowed to design the pattern of injector and producer wells in a waterflooding project currently being implemented. In the paper there are details of this study.
Cost Reduction in Downhole Completion Equipment Supply: A Case History
Authors: Watson Graeme , Hibberd Roger , Turner Will , Hidding Gert Jan
Published: December 2007

Effective coordination of the supply of downhole completion equipment is critical for oil and gas companies. The process usually includes planning, procurement, storage, call off and onshore preparation of completion components and assemblies. At current daily costs for rigs and fixed platforms, the consequences of late supply or failure of just one item can be significant and may exceed the original purchase cost of the entire completion.

Major completion components include subsurface safety valves, landing nipples, circulating devices, expansion joints, production packers, and seal assemblies. Hundreds of components may be handled due to variations in well type, well conditions, casing size, tubing thread, and individual well engineers' preferences. Accessory items such as pup joints, flow couplings, blast joints, and crossovers must also be coordinated. Involvement of several different suppliers can further complicate the process.

Two operating units of a major North Sea Operator have joined forces to implement a new approach to improve efficiency and reduce the overall cost of downhole completion equipment by issuing a joint, pan-European tender. European Community regulations were adhered to in generation of a "functional requirements" tender, as opposed to a full specification tender. This enabled potential suppliers to propose "fit for purpose" equipment which already has a proven track record rather than new designs, which would require testing to prove compliance with a client specific specification. Following the "functional requirements" tender, a commercial tender was completed. The commercial tender included options for the level of materials management covered by the service companies who satisfied the functional requirements.

Details of operating value drivers used to direct focus on potential cost savings are described as well as how total cost of ownership has been reduced to the benefit of both the end users and the lead suppliers.

Performance measures developed for the agreement are discussed, as well as how these measures reflect progress towards stated goals.

The authors feel that the processes and procedures presented in this paper have considerable potential benefit to other oil and gas operating companies.
Reservoir Conformance Approach and Management Practices for Improved Recovery Opportunities: Process and Case History
Authors: Soliman M. Y. , East L. , Gorell S.
Published: December 2007

The realization that the majority of the world's reserves exist in mature reservoirs has resulted in new urgency to develop methods to resolve excessive water production and improve recovery efficiency. Predicting water influx problems, selecting candidate wells for water control treatments, and justifying expenditures are critical factors for developing improved reservoir management strategies.

Optimum reservoir management strategies begin with an understanding of fluid flow behavior in the reservoir under both production and injection conditions. This understanding allows for the creation of conceptual models that illustrate the flow of fluids in reservoirs and serve as a means of communicating management strategies to all participating in operations and business functions. This concept emphasizes the use of the total reservoir approach.

This paper will present a technique that uses reservoir description to develop management strategies for improved reservoir recovery through application of conformance technology. "Conformance" — as used here — may be defined as the management and alteration of water and gas flows using the appropriate reservoir understanding to optimize hydrocarbon production. This approach clearly emphasizes the importance of forming multi-disciplinary teams to resolve excess water production problems. The teams are not only multi-disciplinary but also multi-company, including personnel from both the operating and service companies. The goals of the teams should be to: Build a reservoir model that incorporates the static and dynamic properties of the reservoirValidate the modelUse the model to illustrate the fluid movement in the reservoirDevelop a strategy for managing excessive water productionSelect treatment candidatesImplement the strategyEvaluate results.

The application of this "total" approach is illustrated with a case history. In this case history, reservoir data are discussed, and a conceptual model that describes a problematic water flow mechanism is developed. This model is then used to develop a reservoir management strategy that incorporates conformance technology to improve the existing recovery factor of 9.5% to an expected recovery factor of 40%.
Field Use of Temporary Fluid- Loss Control Pill During Deepwater Completions in HighPermeability Formations
Authors: Araujo A. , Calderon A.
Published: December 2007

This paper was prepared for presentation at the 1999 SPE Latin American and Caribbean Petroleum Engineering Conference held in Caracas, Venezuela, April 21–23.
Particle Size Distribution Selection of CaCO3 in Drill-In Fluids: Theory and Applications
Authors: Cargnel R. D. , Luzardo J. P.
Published: December 2007

Bridging agents are used in Drill-In fluids to prevent problems of massive loss circulation to the formation and formation damage through fine solids migration that invade the hydraulic flow channels of the reservoir rock. Also, thick cake build up that induces a differential sticking problem, as well as torque and drag of the drill string are avoided.

The first step when selecting the particle size distribution of bridging agents (specifically CaCO3) in Drill-In fluids is the petrophysical characterization and pore geometry determination of the rock. In consolidated sands, the criterion of selection of particle size of bridging agents is: 1/7 Dpore throat<Dparticle<1/3 Dpore throat. CaCO3 from different sources were selected with a particle size distribution within the described interval, determined by using a particle size distribution analyzer through LASER dispersion technique. In order to prove experimentally the effectiveness of the formed cake, dynamic filtration tests were conducted in aloxite synthetic cores previously characterized.

Determination of the pore and pore throat diameters were performed through S.E.M imaging technique. Verification of the particle size distribution of the CaCO3 to be used was carried out through LASER dispersion technique. Results of the dynamic filtration tests are reported.
ORIMATITA®. An Improved Hematite for Drilling Fluids
Authors: Tovar Jose , Rodriguez Zulay , Quiroga Freddy , Greaves Roberto , Melendez Henry , Arocha Juan , Bland Ron , Hebert Mark
Published: December 2007

This paper was prepared for presentation at the 1999 SPE Latin American and Caribbean Petroleum Engineering Conference held in Caracas, Venezuela, 21–23 April 1999.
Multilevel Injector/Producer Wells in Thick Heavy Crude Reservoirs
Authors: Fernandez Belkis , Ehlig-Economides Christine A. , Economides Michael J.
Published: December 2007

With modern drilling techniques it is now possible to drill wells with multiple branches emanating from the same vertical or even horizontal trunk. Several heavy crude reservoirs are very thick and had they contained light crudes, their vertical permeability could make them attractive for single horizontal wells. Unfortunately, the much higher viscosity of the reservoir fluid results in highly unfavorable mobility. Thus, drilling several horizontal branches at different levels of the reservoir would effectively create thinner drainage areas and this, in itself, would be attractive because in thin reservoirs the vertical mobility is far more forgiving. However, a clear benefit in heavy crudes is derived from thermal recovery and a scheme is suggested here, where either steam is injected at the top of the reservoir or hot water is injected at the bottom through a dedicated horizontal well injector. (From an operational point of view it is desirable to use the same vertical trunk for both injection, e.g., through the tubing and production through the annulus, or vice versa.) The optimization strategy is to estimate the desirable number and spacing of the producing laterals. The vertical spacing is not even, but instead, it depends on the crude oil viscosity, that, in turn, is affected by the heating process. We present in this work a methodology of multilevel well optimization and several case studies for different numbers of laterals and their vertical spacings.