ECOLOGICAL GAS TREATMENT PROCESS WITH OUTSTAN DING VERSATILITY AN D ECONOMICS E. Lebas, J. Larue and A. Minkkinen Abstract. For pipeline corrosion and hydrocarbon dew point control, dehydration is often the prerequisite step to any gas processing scheme be it onshore or offshore. Sweetening or bulk acid gas removal is also often needed to meet pipeline transport specifications. The IFPEXOL process deals with these two operations in a very versatile and cost effective way using methanol as a single solvent. This process can be split into two parts: IFPEX-1 for dehydration and NGL recovery and IFPEX-2 for acid gas removal. IFPEX-1 uses methanol as hydrate inhibitor in a cold process for water and hydrocarbon dew point control. Methanol is recovered from the condensed water phase using a stripping column where it is contacted with part of the raw wet gas at ambient temperature, avoiding the need of a distillation column. This process is environ- mentally friendly because no heat is needed, there are no vent gases and the rejected water can be reused. The IFPEX-2 process is based on the high solubility of H,S and CO, in cold methanol, and on the variation of solubility due to methanol concentration in water and solution temperature. Depending on the specifications needed for acid gas removal, this process may have different configurations. Selective H,S absorption as well as CO, and H,S removal can be achieved. The liberation of acid gases can take place at a pressure up to 15 bar which makes IFPEX-2 well adapted for acid gas reinjection. In another configuration, it enables acid gas recovery to Claus sulfur plant at appropriate quality. 40
FUTURE OPTIONS FOR THE USE OF MIDDLE EAST NATURAL GAS RESERVES M. Mehrvarz, Iranian Petroleum Institute; A. M. Samsam Bakhtiari, National Iranian Oil Company Abstract. The share of natural gas in global energy consumption has been rising steadily during the past decades and still remains on growth track. Of the world's two major natural gas provinces, the largest (Russia) is being exploited, while the other (The Middle East) is still rather untapped-hence its bearing on future gas supplies. Initially in this paper, the present status of natural gas in Middle Eastern countries is reviewed and the imbalance between proved reserves (32.4% Worldwide) and actual 1995 production (6.6% of World) is under- lined. Furthermore, the gas industries of its major countries are highlighted. Turning to the future, the major options available to Middle East natural gas reserves holders are investi- gated. It is clear that from an economical point of view, domestic options look more attractive in the Middle East than export projects. The question of the future gas prices is reviewed as this matter will influence the feasibility of major export schemes. An attempt is made of outlining the future supply of natural gas from the Middle East, either in pipelines or LNG form (up to the year 2010). and it is concluded that the Middle East's present share in gas world trade is bound to grow considerably. 1.
Natural gas began life as an unwanted by-product of crude petroleum production and as an unusable mineral resource. At the turn of the century, it even- tually became a source of primary energy in the U.S.A. After the end of the second world war it grad- ually became a component of the global energy mix, with a noticeable growth in the West European market. Then, in the 1970s, Japan became a major user of natural gas too. Within a span of seven decades, natural gas's share of worldwide energy needs has steadily increased: from around 2% in 1920 to 23.3% in 1995l-as shown in Fig. 1. Projections for the future uses of natural gas show that its share of the global energy mix could still increase in the early 21st century: assuming `business as usual', its share could rise from the present 23.3% to around 25% of global primary energy require- ments by the year 2010'. 2. PRESENT STATUS OF PROVED GAS RESERVES As far as natural gas reserves worldwide are con- sidered, two major provinces dominate the scene: Russia and the Middle East. These two major prov- inces account for roughly two-thirds of proved world gas reserves: their respective shares amount to 34.4% and 32.4% of total reserves. A breakdown of these reserves by region is presented in Table I and a simple graphical view is shown in Fig. 2. As can been seen from Table I, besides the two dominating provinces, the rest of world gas reserves seem to be evenly split amongst the six other regions. 3. TWO MAJOR PROVINCES If the proved reserves of
NAUTILUS A NEW TECHNOLOGY FOR SUBSEA PRODUCTION: DEVELOPMENT AND TEST RESULTS J. N. Renault, Total, Paris La Dgense, France Abstract. NAUTILUS is a subsea 1.3 MW electrical multiphase pumping unit which operates an helicoaxial multiphase pump with a high speed, directly coupled induction motor fed from an offshore platform mounted voltage inverter through a submarine three phase cable. The system operability and reliability demonstration up to 50 km was carried out under submerged condi- tions on an hydrocarbon multiphase loop. This new technology available to-day can play a key role in offshore production due to the economical impact on deep water and satellite field developments; it can also substantially increase the potential of exploitable reserves. This paper will present the technical results of the development and the advantages of this technology in subsea fields development.
A subsea boosting system can grant access to mar- ginal or satellite offshore fields. This is especially the a satellite well located within 50 km from its case when a deep water production support on site is not cost effective when compared to direct export to `mother' production platform. a shallow water platform or directly to shore. Typical reservoir parameters for the application of a NAUTILUS multiphase booster station are indi- cated below: OBJECTIVE AND CHALLENGE NAUTILUS has been designed for installation on - Gas oil ratio (GOR) at standard conditions, 300 to - Gas liquid ratio (GLR) at pump suction, 2 to - Pump suction pressure, 150 to 725 psi - Pump discharge pressure, 725 to 1450 psi - Total flow at suction, 50 O00 to 200 O00 bbl/d Multiphase production represents an economically attractive solution when the wells are eruptive at the sea bottom: subsea multiphase pumping can signifi- cantly boost well productivity and substantially increase the potential of exploitable reserves. This is generally the case when the following reservoir and process conditions are met: - Lack of energy due to low GOR, - High water depth, - Long distance to final production facilities (high back pressure at the well-head), - Increasing or high water-cut. Used as an early production system, NAUTILUS can delay and/or facilitate the decision to implement a full development and reduce the time lag between the reservoir discovery and the first oil production. 1400 scft/bbl 12 vol/vol The objective of the NAUTILUS Project is to design, build and evaluate a subsea multiphase elec- tric booster system to demonstrate its operability and reliability. The challenges were the development of a subsea multiphase boosting system for variable speed over long distances (50 km) and the development of key components required for the electrical power trans- mission with its associated control and communica- tion system. THE NAUTILUS CONCEPT Boosted by a subsea helico-
COMPUTER AIDED MINIMIZATION OF CRUDE OIL AND PRODUCT PIPELINE TRANSPORT COSTS A. Linke, Munich Abstract. Oil and product transport in a trunk pipeline causes high energy costs. The transport costs should be considered in the Transport Schedule. The pipeline scheduler has to find a Transport Schedule that fulfills the transport orders from the shippers and minimizes the costs. To relieve the scheduler from routines like cost calculation and support his decision-making a computer program is suggested. The kernel of the computer program CUBE consists of a knowledge base and a cost model, which includes the energy tariffs, the pump characteristics, the contamination rules and some general transportation rules. The computer program manages the tank farm intake on the basis of the contamination rules and minimizes the Transport Schedule costs under given constraints for time and quantity. The daily or weekly Transport Schedule is carried out by the operator. The computer informs the operator about the optimum pump configuration and pressure setpoints in a specified rate window. Detailed feedback from the operation about power consumption gives the scheduler the opportunity to control the pump costs and run the pipeline in the most efficient way. 1.
Pipeline scheduling is a complex task usually per- formed by an experienced scheduler. The pipeline scheduler is the central link between the shippers, the refineries and pipeline operations (Fig. 1). He is responsible for all aspects of throughput, quality and cost management. Considering the guidelines for contamination and the general transportation rules he prepares a transport schedule. It remains a chal- lenging task to minimize the pump power costs of the schedule and ensure full product supply. It might appear that nowadays a good computer program can do this job as well. But conflicts in the schedule and unpredictable events will prove every computer program as too inflexible. Therefore, it is preferable to provide the scheduler with an efficient software tool which exempts him from routine jobs and supports his decision-making. Refineries Shippers Fig. 1. Relations of a scheduler. The transport schedule is a steady state solution. It does not consider pressure and throughput changes in a multicrude or product pipeline caused by differ- ent batch properties. For this reason, the operator receives as information only a mean throughput and upper power limits for each Pumpstation from the scheduler. Within these restrictions, the operator has the opportunity to tune transport costs as well. With the help of a computer program the operator achieves the optimum pipeline efficiency, using the best pump configuration and corresponding pressure control valve (PCV) setpoints. The concept of a multistep cost optimization and its software solution is pre- sented. 2. SCHEDULE OPTIMIZATION 2.1 Transport schedule Before explaining the concept of cost control it may be helpful to spend
COMPLEX WELL ARCHITECTURE, IOR AND HEAVY OILS Gérard Renard and Eric Delamaide, Institut Français du Pétrole, 1 and 4, Avenue de Bois-Préau, Rueil-Malmaison, France; Rob Morgan and Jean-Pierre Fossey, CS Resources Limited, 29th Floor, 645 - 7th Avenue S. W., Calgary, Alberta, T2P 4G8, Canada Abstract. In the last few years, new developments in drilling technology have allowed drilling and casing of multiple lateral wellbores from a single, horizontal or vertical, primary wellbore. Initially, multiple laterals were drilled for primary production to take the laterals cost effectively to the oil, increasing the reservoir exposure (and productivity) and accelerating recovery. Nowadays, these wells are paving the way to new possible complex well pattern architectures. In combination with revisited Improved Oil Recovery (IOR) or Assisted Gravity Drainage (AGD) processes, they can provide economical means to produce a part of the huge reserves of heavy or viscous oils in place all over the world. The general concerns while implementing IOR or AGD processes are: the reservoir conformance (pattern confinement), the sweep eficiencies (area1 and vertical) and problems of injectivity and/or productivity. This paper presents the consequences of using new technologies to gain access to a reservoir in conjunction with well established recovery mechanisms and mobility enhancements to produce low mobility hydrocarbons. Synergy between new well architectures and various processes (IOR or AGD) to improve recovery is presented in detail. Applications to actual field cases are provided to illustrate the potential of this synergy. Finally, specific prob- lems related to multiple lateral wells are outlined. INTRO D U CTIO N The ever-growing interest in heavy oil resources can be easily explained by their size, potential as a future world energy supply, and because geographi- cally they have a strategic distribution in comparison with the distribution of conventional light and medium world oil reserves. World reserves of heavy ["API < 20 (>934 kg/m3)] and extra-heavy ["API < 10 (> 1000 kg/m3), ,u < lo4 mPa - s] crude oils and natural bitumen ["API < 10 (> 1000 kg/m3), ,u > lo4 mPa . s] are estimated' to about 100 Giga- tonnes (GT). Major reserves are located in Canada, Venezuela and Former Soviet Union (Fig. i). Canada's natural bitumen reserves are mainly in the Athabasca region. The FSU natural bitumen resources are concentrated in the Volga-Ural and East Siberia. Venezuela has most of its heavy oil and bitumen in the Orinoco Belt. The cumulative pro- duction as of today is close to only 7 GT (Fig. i), with a major part produced by Venezuela and U.S.A. While these reserves are approximately equal to the identified reserves of conventional crude oil accredited to the Middle East' (96 GT), their contri- bution to the world supply is low, less than 5%. Until recently, this could be explained by the fact that unconventional r
CUBA Speech by MARCOS PORTAL LEON, Minister of Basic Industry of the Republic of Cuba Mr. Chairman, Excellencies, Ladies and Gentlemen : Cuba is a small Latin American country engaged in major efforts to overcome underdevelopment and secure a decent life for its people by building on high health-care, educational, cultural and social security standards for all. Over the last 38 years, my country has established a satisfactory infrastructure for industrial, agricultu- ral and social development that requires a relatively high energy consumption. Cuba does not have big rivers, coal or large forests, and to-date, its crude oil production (31 O00 bbl/d) covers only 15% of its total needs. For 30 years until 1990, my country procured its oil requirements for a rapid development-up to 13 million tonnes a year-from the Soviet Union under quite favorable terms of trade. Since 1991, Cuba has been obtaining its crude oil and by- products from the international market, and last year these imports represented more than one billion dollars. Close to 20% of that cost was the result of additional financial expenses arising from a lack of medium and long term credit facilities and other dif- ficulties created by the embargo imposed by the US government on my country, which also has an impact on Cuba's oil imports. Against the background of Cuba's ongoing econo- mic opening to foreign investment since 1991, a Cuban state-owned corporation, CUBAPETROLEO, has signed over 40 economic association contracts with foreign oil concerns, including 22 venture contracts for on-shore and off-shore exploration executed with companies from Canada, the United Kingdom, France, Sweden, Spain and other countries which account for 70% of the blocks in offer. We are con- fident that the next few years will see important discoveries. Furthermore, CUBAPETROLEO has entered into agreements with foreign firms to utilize the associated gas in power generation as well as household fuel, and other incremental production contracts for the operation of existing deposits with the use of advanced technologies. In addition, CUBAPETROLEO operates four oil refineries and a network of oil terminals and depots, including a super-tanker terminal that can accommodate up to 150 thousand ton tankers. CUBAPETROLEO is also responsible for the dis- tribution in the domestic market. Distinguished delegates: This 15th World Pet- roleum Congress has been called under the motto 'Technology and globalization : Leading the pet- roleum industry into the 21st century'. Obviously, as we recognize the fact of globalization and the tech- nology changes operated in its context, we cannot fail to realize that the existing and fast-moving glob- alization is one that takes place under the prevalence of a neoliberal policy that causes serious effects on the Third-World countries, albeit not just those nations. As you known, the neoliberal globalization nur- tures financial speculation, and man
I NTE R P R ETATIO N O F CO M PLI CATE D G EO LOG I CAL STRUCTURE FOR DEEP STEEP STRUCTURE'S HINTERLAND IN SICHUAN Gang Lin, Zhang Hong and Fan Mingxiang, Chengdu Computing Center, Geophysical Prospecting Corp., Sichuan Petroleum Administration, CNPC, P.R. China Abstract. This paper gives out seismic information interpreting methods for deep steep structure in Sichuan, including connecting seismic data, processing and interpreting, marking stratigraphic, appreciating velocity information, making structure pattern, interpreting with seismic and geology, backing well information and so on. INTRO D U CTIO N The east Sichuan Basin consists of deformed, comb-shaped, asymmetrical high-steep structural area with complex geological framework. The sub- surface structures are complex and the quality of the seismic data is poor. The Carboniferous carbonates are the most important gas reservoirs, but they form a thin interval having rapid lateral changes in physi- cal properties. Therefore, an accurate description of the structural shape, lateral distribution and physical properties of the reservoir is crucial in increasing the success rate of exploratory drilling. This paper summarizes the methods utilized to accurately interpret the structural shape and to increase the accuracy of prediction of the lateral extent of the reservoirs using the DTC structural zone example which is typical of the highly steep structures in eastern Sichuan Basin. Accurately interpreting the structural shape The seismic processor and interpreter work closely with each other integrating the analysis of stacking velocity, building of the migration model and time to depth conversion. Thus, the resolution, S/N ratio and imaging quality of seismic sections have increased significantly. The target formations have been accurately identi- fied using the VSP log and synthetic seismograms. The reliability and consistency of identifying the target formations were verified by checking the seismic line ties. 3. The structural model is being built by a com- bination of the drilling data with wave field fea- tures of the seismic sections, and through forward modeling. Once the model is established, it is modified till a final model is reached, which is then used to guide the interpretation of the sec- tions. 4. Important geologic features and structural details are accurately interpreted in the seismic lines. In the eastern Sichuan Basin the small folds, reverse thrusts, and small-scale faults are developed. Denudation and pinchout events are seen throughout the lines. There are rapid changes of the secondary thickness of the Triassic anhydrite formation. For this reason, the processor and the interpreter must understand the character of the reflection waves carefully, resolve and interpret complex wave fields to increase the interpretation accuracy. 5. Velocity data is analyzed and correctly applied. The important factor that affects the accuracy of the structural results is
AN INNOVATIVE APPROACH TO ENERGY CONSERVATION AND ENVIRONMENTAL PROTECTION UTILIZING NATURAL GAS IN MUNICIPAL AND OTHER TRANSPORT FLEETS Amir Badakhshan, Professor, Chemical and Petroleum Engineering Department, The University of Calgary, Calgary, Alberta, Canada T2N lN4; Edward Mirosh, Vice-President, Alternative Fuel Systems, Calgary, Alberta Abstract. Medium and heavy duty vehicle fleets of trucks and buses are large users of diesel fuel energy. As the third world continues development, increased needs for transport will create a sharp increase on world fuel energy consumption and emissions. Natural gas is the most stable and promising alternative fuel which is not only widely available, but is also widely traded and is competitively priced. In fact, where pipeline gas is available, compressed natural gas (CNG) on board a vehicle, can be less costly than the equivalent as liquid fuel. Because natural gas mostly consists of methane, vehicle tail pipe hydrocarbon emissions are mostly non- reactive with very low atmospheric smog potential. Moreover, the slightly lower combustion temperature of natural gas results in lower NO, emissions at similar engine operating conditions. Because natural gas has a lower carbon content than diesel or gasoline, and requires less refining energy, the efficient use of natural gas will provide a substantial reduction of greenhouse gas emissions and results in lesser global warming potential. The development of the multipoint diesel dual fuel (MDDF) management system not only uses natural gas efficiently as in the diesel cycle, but also retains vehicle driveability and supports clean combustion which results in lower engine tail pipe emissions. When on board natural gas is available at a 35 to 50% lower cost than diesel fuel, and vehicle conversions may be depreciated in less than two years. 1.
Fuel efficiency of internal combustion engines powering vehicles, is largely a function of external forces acting upon the vehicle, the engine thermody- namic cycle and the load cycle of the vehicle. Diesel engines evolved for large trucks and buses because they are more energy efficient than gasoline engines, thus more cost effective in transportation and more competitive for commercial freight. Over the last 20 years the diesel engine tractor trailer unit has developed to the point that 50 litres/ 100 km of consumption is reduced to 35 litres/ 100 km due to many factors including reduction of drag coefficient, higher engine and transmission effi- ciencies and lighter vehicle weight '. However, today's engine building fraternity has set the clock back by more than twenty years, with the development and promotion of the fuel inefficient otto cycle CNG engine. Operators of fleet vehicles in load cycle sensitive applications have particularly been disappointed by the 30% higher capital cost, and also by the increased operating costs of the otto cycle CNG engine. Not knowing the nuances of th
HCTB-A NEW PROCESS TO PRODUCE HIGH QUALITY DIESEL OIL AT LOW COST P. R. G. Bonfadini, Leopoldo A. Miguez de Mello Research and Development Center (CENPES), Petrobras SIA, Rio de Janeiro, Brazil Abstract. The search for an alternate route to increase diesel oil production per barrel of crude oil processed has been stimulated by a steady growing of diesel demand in Brazil and limited supply in the international market. With this objective a new process, combining a mild thermal cracking and hydrotreating technologies, has been developed at Petrobras Research and Development Center in Brazil. The main focus on this new process, which is called HCTB, is to increase the production of high quality diesel oil in a refinery at minimum cost. The others known processes like the MHC (Mild Hydrocracking) and HCC (Hydrocracking) processes have a higher investment and operational cost. The HCTB process consists in vacuum gasoil mild thermal cracking in two reactive zones followed by fractionating and diesel stream mild hydrotreating. A process description and the results of the pilot plant and the 1900 BPD (300 m3/d) demonstration plant runs with gasoil from Brazilian crudes will be shown. The process economics will be presented. Other combination possibilities of the mild thermal cracking process with the hydrocracking process will be also discussed. 1.
The development of the catalytic cracking process in the middle of this century has rendered the thermal process obsolete for gasoline production. The diesel oil produced by the catalytic process has a worse performance in the diesel engine then that pro- duced by the thermal process. With the growth of the diesel oil demand, the search for alternative processes for diesel oil production made us revive the thermal cracking of vacuum gasoil, but now diesel pro- duction is to be maximized. In the end of the So's a continuous growth in the diesel demand and a decrease in the gasoline demand were expected in the behavior of Brazilian domestic petroleum derivatives market. As the conventional route for diesel production, top distillation, would not be able to meet the future Brazilians needs of this product, and the known alternative conversion pro- cesses to produce high quality diesel, like the HCC process were too expensive, Petrobras decided to develop a research program aiming at a new process to produce high quality diesel at minimum cost. 2. PROCESS DEVELOPMENT In the HCTB process the main objective is to convert vacuum gasoil in order to obtain high diesel yield with high cetane number and chemical stability. So the process development aimed at minimizing gasoline production and at avoiding the chemical reactions that would worsen the diesel quality. This goal was reached by selecting proper mild thermal cracking conditions (low temperature and pressure), and designing proper equipment to carry out the chemical reactions (see Fig. 1). The experimental development began seve
SUCCESSFUL WATERFLOODING IN A HETEROGENEOUS RESERVOIR Jose Mellado, Pluspetrol E&P, Argentina Abstract. This paper presents the results of Reservoir Management in the Centenario Field (Neuquen Province, Argentina), operated by Pauspetrol in December, 1977. The field was produced by primary recovery from 1967 to 1980, when conventional water injection was initiated in two partially-depleted fault blocks. Since per- formance at the outset differed from that predicted, a detailed Reservoir Characterization study was carried out and an operating plan implemented that included strategy of continuous monitoring of performance and adjust- ment of operating parameters that continues to give excellent results. Results, observations and conclusions. Continuous updating of the reservoir model has made it possible to successfully drill 58 new wells and perform 168 workovers and modifications to the water injection system, which have resulted in production of an additional 2.5 million m3 of oil from June 1983 to date. This clearly illustrates the necessity of permanent monitoring and constant modification of the operating plan of water- flooding in heterogeneous reservoirs. The success or failure of this type of project is critically dependent upon understanding the reservoir rock and fluid system, as well as constant monitoring of performance, which in this case has led to recovery of more than 50% of original oil in place. Due to the wide areal dispersion of reservoir parameters, the traditional practice of pilot flooding to predict full-scale performance is not applicable to highly heterogeneous fields. Pilot performance depends upon the locations of the production and injection wells and cannot be extrapolated. For the sake of simplicity, and in order to illustrate the methods used to determine petrophysical properties, areal distribution of pore space and reservoir barriers that affect oil recovery, this paper will be limited to the southeastern sector of the field, the area that posed the most problems. Applications and technical contributions. The results show that multidisplinary reservoir management, together with application of the principles of continuous improvement, can be applied to the exploitation of oil fields with excellent results. The technical contribution is to introduce the concept that dynamic injection schemes in highly heterogeneous reservoirs can increase ultimate recovery in waterñooding projects.
This paper presents the results of Reservoir Man- agement in Centenario Field (Neuquen Province, Argentina), operated by Pluspetrol E&P since December, 1977. The field was produced by primary recovery from 1967 to 1980, when conventional water injection was initiated in two partially-depleted fault blocks. Initial waterflood predictions were based on the reservoir model developed during primary oper- ations. But as water injection progressed, new wells were drilled, pressure measurements and core analysis