This paper discusses the complex evaluation of a basement reservoir in south-eastern Hungary. The host rock is gneiss with negligible porosity; hence the recoverable petroleum rests mainly in fractures. Commercial exploitation of the field started in the early 1980s. After producing more than 1.3 MMm3 oil, currently has reached the phase of significant production decline.
Since the oil accumulated in and is produced through major fracture zones, conventional G&G studies in general and petrophysical studies based on cores in particular do not provide insights to the reservoir's flow system. Consequently, first a large scale geological subdivision was done on the basis of compartments defined from the results of history matching and reservoir simulation. This primordial model has been refined using 3D seismic data to identify major conducting paths (=fractured zones) and to quantify heterogeneity by combining coherence with the acoustic impedance. On the basis of this simplified model a lot of future production scenario has been predicted.
To reduce the risk profile of the forecasts a Discreet Fracture Network (DFN) Model has been constructed. To establish it the reservoir structure and bulk and pay volume of the field had to be verified, the porosity, fracture intensity had to be re-assessed. The input data and their sources have been as follows:
The success of the drilling operations mainly depends on rheological parameters of fluids (mud), the choice of an adequate mud to the specific particularities of a crossed formation and to a geological conditions permits therefore, not only to increase the efficiency or drilling apparatus, but also to avoid the damage (plugging) of producer layers allowing a better productivity of a drilled well. The aim of this first part of this work is to study the influence of the pressure and the temperature on rheological behavior of drilling fluids used to drill the reservoir, composed of emulsions of air, water and different additives.
The second part of this work is to present a general analysis of how the oil recovery and the overall efficiency of miscible gas injection process is influenced by the well pattern configuration. Due to the impact of using horizontal wells an the increase of the ultimate oil recovery, the improvement in the technology of horizontal well construction is one of the advanced technologies in the petroleum industry during the lest decades. Using horizontal wells in miscible gas injection process, higher sweep efficiency for less cost is expected as opposed In the use of classical pattern by using vertical wells. This part first evaluates weIl configurations in synthetic homogeneous model. In total, four cases have been considered in this study using different combinations of horizontal and vertical wells. In the second step of this part, performance of different development scenarios was investigated by optimizing the type of injection wells in Hassi Messaoud field.
FIRST PART: NEW CONCEPT TO EVALUATE HPHT DRILLING FLUIDS USED TO DRILL HORIZONTAL DEEP WELLS Introduction
During the drilling, a fluid circulates form the surface to the bottom of the well inside the string and from the bottom toward the surface in the annular space between the string and the formation drilled. This fluid creates a hydrostatic pressure permitting to assure the stability of formation surfaces on one hand, and prevent the arrival of fluids coming from hole walls. Therefore the knowledge and the control of rheological properties, success and the modelling of out-flows have a major impact on the good progress of drilling operations. Drilling muds are non newtonian fluids, viscous or viscoplastic, and most often thixotropic [1-8]. The usual methods of determination of rheological characteristic that suppose a Bingham fluid have only a value of comparison. They can be kept for measures of control. But, for problems requiring the application of rigorous formulas a more precise rheological characteristics knowledge is of great importance.
Experiments and methodologies
Characterization and modeling of rheological behavior of fluid under surface conditions
The mud system 'Versadrill 80/20(Oil/Water)'is used to drill the reservoir. The composition of this system is: oil, brine (320g/l NaCl), Versamul (primary emulsifier), Versacoat (secondary emulsifier), lime, Versatrol (reducer filtrate) and VG69 (viscosifier). Different rheological are carried out on a system of mud Versadril 80/20 used to drill the reservoir under surface conditions have been done with the help of the FANN35 viscosimeter.
The propene (C3~) is a main feedstock for production of many important intermediate petrochemical products. It is mainly produced by non-oxidative catalytic dehydrogenation of propane (C3). The existing commercial processes are extremely complex as they operate under severe thermal conditions and are highly energy consuming, and are thermodynamically limited by equilibrium.
Oxidative dehydrogenation of propane (ODH) into propene is an alternative route to propene production at lower temperatures. The important objective of this work is to study and compare the catalytic activity of vanadium oxide supported on Kieselguhr, MCM-41 and γ-alumina for oxidative dehydrogenation of propane into propene.
Series of supported vanadium oxide catalysts (5 wt. %) have been prepared using Kieselguhr, mesoporous MCM-41 and γ-alumina as supports. The oxide materials obtained by calcination at 700ºC for 3 hours were characterized by means of physisorption, XPS spectroscopy and X-ray elemental analysis. The catalytic behaviour of the prepared supported catalysts was investigated in a fixed bed reactor under different conditions of temperature ranging between 400-700ºC with propane to oxygen ratios ranging between 0.7 - 3.6 at atmospheric pressure.
The results showed ODH and combustion as major reactions. Small amounts of cracking products (methane, ethane, and ethene) were also produced over temperature of 550ºC with no oxygenated products other than carbon oxides were found over the two supported vanadium oxide catalysts. The results also showed that the conversion of C3 and selectivity to C3~ varied upon changing the reaction temperature and C3/O2 mole ratio.
It could be concluded from the series of ODH of C3 into C3~ that, the catalytic performance of vanadium oxide supported on Kieselguhr is much better than that supported on MCM-41 and γ-alumina under the same conditions of temperature and C3/O2 mole ratio and slightly exceeded that of vanadium oxide supported on metal oxide such as Al2O3, TiO2, SiO2, MgO and ZrO2 reported in the literature. The maximum selectivities to C3~, cracked hydrocarbons and carbon oxides are (31%), (14%) and (16.3 mol%) respectively with conversion of C3 (22 mol%) at temperature of 600°C and 2.3:1 mol ratio of C3/O2 over vanadium oxide supported on Kieselguhr, while with vanadium oxide supported on MCM-41 are (8.5%), (31.6%) and (47.7 mol%) respectively with conversion of C3 (51 mol%) at temperature of 700°C and 1:1 mol ratio of C3/O2 and with V2O5/ γ-alumina (12%), (1.8%) and (23%) respectively with conversion of C3(20%) at temperature 500°C and 1:1 mol ratio of C3/O2.
The importance of propene
Propene is very important feedstock in petrochemical industry and largely requested to produce many important intermediate petrochemical products such as polypropylene, propylene oxide, acrylonitrile, acrylic acid and acrylates, butyraldehyde, and isopropyl alcohol. Therefore, propene is the basic building block for many end use products such as, plastics, packaging materials, paints, solvents, detergents, cosmetics, pharmaceuticals and building products. The global demand over the next 15 years for propene is forecast at annual growth rate of 5% per year.
Several offshore platform concepts for LNG import are currently under development. Among these are concrete gravity based structures (GBS) containing storage tanks for LNG and with topside facilities for receiving and regasifying LNG, and exporting natural gas to onshore distribution systems via an offshore pipeline.
The first application to be realised is the Adriatic LNG Terminal off the East Coast of Italy. The terminal will be located 17 km off the coast in 29 meter water depth and will be installed during 2007. The source of the LNG is Qatar.
Technical Key Figures:
•Receives 1 LNG carrier (145,000m3) every 3rd day
•LNG storage: 250,000 m3
•Size: 180m long, 88m wide
•Concrete volume: 95,000 m3
•Topsides weight: 12,000 tonnes
•Regas capacity: 1.1 mill m3/hr
The Italian terminal substructure is planned to be constructed in Algeciras in Spain. When the GBS has been constructed and the regasification plant installed on it, the construction will be floated and towed to its location in Italy, where it will be placed on the sea bottom as an artificial island.
The technology for concrete construction and the marine operations associated with these heavy, floating objects, has been created over the years through the development of concrete oil and gas production platforms in the North Sea and other places in the world.
Further prospects are being worked on for application in North America.
The main advantages of the offshore GBS solution are to:
•Avoid the risk of explosions, fires etc in the vicinity of civilian communities
•Eliminate the need for onshore acreage in congested regions
•Shorten the time for realisation of projects due to less complicated regulatory approvals procedures •Optimise access for LNG carriers
The paper will discuss technologies involved and parameters that will influence the feasibility of the concept under different conditions.
The need to exploit remote gas reserves is increasingly urgent as well as supplying the clean gas in a safe and environmental friendly way as close as possible to the larger consumer regions. The increasing demand to utilize stranded gas from remote locations and supply environmental friendly energy to existing gas grids as close as possible to the larger consumer areas, is requiring new innovative solutions.
he production site is often located remote from the consumer markets. Hence the transport is very important. To minimize the transport cost, the gas is reduced in volume by liquefaction, which is obtained by cooling down to minus 160 Co. The market is hence demanding plants for both liquefaction and regasification of the Natural Gas. The plants needed for this represent a growing market. But to get a viable business out of this, the entire chain from production to delivery of gas to the market has to be in place before any major funding decisions are made.
The LNG chain
Liquefied natural gas (LNG) is the most used method for gas transport over longer distances. An LNG chain starts at the liquefaction plant located nearby the gas production source as shown in fig 1 below.
The efficient use of energy in the petroleum industry is becoming increasingly important. Energy consumption is an important factor which intervene in the crude oil refining cost. In this paper, the different areas where energy consumption can be reduced in the petroleum refining and petrochemical industry are described. Guidelines for energy survey are given.
Energy losses once identified can be reduced with little investment. Up to 15% savings can be obtained through an energy saving program. Important savings can also be made with operational improvements in the process and better maintenance of production equipment such as furnaces, boilers and heat exchangers.
The use of new designs equipment in the process such as compact heat exchangers and cogeneration systems can improve performance and increase the profitability in an existing refinery. Saving energy in the process will also reduce the amount of gas emissions.
A study on energy savings and its environmental impact in a local refinery is presented.
The energy saving became a need which is essential to take into account in the management of the existing refineries and also in the design of new refining units. The research of energy saving is divided primarily into three categories:
Bio fuels like ethanol and bio diesel produced from renewable sources are being promoted world over to provide freedom from dependence on imported oil and to reduce pollution. Blends of ethanol in gasoline have been used for several decades. Bio diesel has been recognized as an alternative which not only has some of the properties superior to petroleum diesel but also reduces emissions of carbon monoxide and particulates. India has started blending of 5% ethanol in motor gasoline and efforts are being made to increase this blending upto 10%. Further work is also being conducted to use ethanol as a blending component for diesel fuel which has high demand in India. It has also been recognized that in a country like India, we may produce bio diesel from non-edible sources like jatropha and pongamia pinnata so as to reduce the consumption of diesel fuel. IOC R&D has conducted elaborate studies to assess the impact of blending of ethanol in gasoline and diesel on vehicle performance and emissions from scooters, motor-cycles, passenger cars and light commercial vehicles. A pilot plant for production of bio diesel has also been set up at IOC R&D in which small batches have been produced. Vehicle performance and emission testing has also been done on several diesel vehicles. A pilot project for use of bio diesel-diesel blends in a small fleet of buses is currently in progress. The data generated with use of blends of bio fuels like ethanol and bio diesel in petroleum fuels is discussed in this paper. Based on the studies conducted so far, it is concluded that upto 10% of bio fuels-petroleum fuel blends can be used in existing vehicles without any modifications.
The world is confronted with twin crises of fossil fuel depletion and environmental degradation. Bio fuels like ethanol and Biodiesel produced from renewable sources are being promoted worldover to provide freedom from dependence on imported oil and to reduce pollution. Ethanol has been used for several decades as a blending component for motor gasoline particularly in countries like Brazil which are blending upto 24% of ethanol. In India, although several studies had been conducted in the past, the ethanol in sufficient quantities had not been available. During the year 2000, the distilleries in India reported surplus availability of ethanol and Government of India advised Indian Oil Corporation Limited, R&D Centre (IOC R&D ) to undertake studies on new generation vehicles with 5% and 10% of ethanol in gasoline. As the diesel consumption in India is much higher than gasoline, it was also decided to undertake studies related to use of ethanol in diesel. Since ethanol blends in diesel are not being used anywhere on large commercial scale on account of difficulties in making stable blends, it was decided to restrict such studies upto 5% of ethanol in diesel. Another bio fuel which has attracted considerable attention in the recent past is Biodiesel produced from vegetable oil sources.
Possible method for determining the energy efficiency will be presented taking one refinery unit named Catalityc Reforming as an example.
From the aspect of energy, the efficiency and optimization of Catalytic Reformer is analysed through the cost price of medium pressure steam and the possible money savings that can be realized by eliminating differences between the target standard (average energy consumption standards of Western European refineries) and specific energy consumption.
Steam gross consumption of observed Catalytic Reforming process is 40 000 t or 119 TJ. By observing the energy flows and Sanky s diagram of energy flows of Catalytic Reforming process, it can be seen that by the own generation of medium pressure steam Catalytic Reforming ensures 10 000 t or 30 TJ i. e. about 25% of own gross consumption, at the cost price of 0.45 USD. The remaining quantity of steam required, in the amount of 30 000 t or 89 TJ, is supplied from refinery Power Plant at the cost price of 9.66 USD. The average cost price of medium pressure steam used for own consumption of Catalytic Reforming is 7.36 USD.
Main reason for such a cost price of medium pressure steam generated in Catalytic Reforming unit itself (0.45 USD) lies in the fact that steam in this unit is generated as byproduct, by utilizing the heat of flue gases in the boiler, which eliminates the consumption of fuel oil. In the calculation of the cost price of steam generated in refinery Power Plant, fuel oil shares with approximately 80%.
Concerning the possibilities of monitoring and increasing of energy efficiency and optimization, through net consumption target standard (average energy consumption standards of Western European refineries) and specific gross and net energy consumption of outlined unit, upon analysis it can be shown that inefficiency index is 115%. Possible money savings realized _
In addition to being one of the main energy generators, and a significant bearer of energy in final use, oil processing industry is at the same time a great energy consumer. The importance of oil processing industry as one of the main pillars of national energetics, obligates it to process oil in a conscientious, economical way. The mere fact that oil refineries mostly use their own (energy-generating) products does not free them from the obligation to consume these energy carriers rationally. Rational consumption of oil derivatives should start at the very source, in the process of derivative production, and it should be manifested in a reduction of own energy consumption in the refineries. The quantity of energy saved by the very producer of energy will ensure the reduction in the consumption of primary energy in the amount that corresponds to the quantity of the produced secondary energy.
It has been shown in practice that product prices incorporate all the faults and drawbacks of internal economy without any significant attempts to find the ways to stop increase and even cut the prices, by way of a better utilisation of production capacities, greater productivity, better organisation, etc.
Technological advances in gathering, processing and storage led to the creation of databases with massive amounts of information. As operations become increasingly driven by the newest technological solutions and the most complete and accurate databases available, it is essential that this knowledge base be readily available to all end users at the right time and the right location. This session will review the latest advances in data handling systems and how companies are ensuring that the knowledge accumulated internally can be disseminated to all users through knowledge networks or similar approaches.
How Knowledge Management can help E&P companies overcome the productivity challenge they are facing
The industry is facing a double productivity challenge:
A challenge to make existing assets more productive to cope with surge in demand and declining production rates
A challenge to make the E&P people more productive, as many skilled workers are leaving and not people have been trained in the last year by the industry.
Looking at decline in production rates & demographics of the industry, the scissor effect means that the industry will have to get 10%more productive each year in the next 10years, a challenge that no industry have faced up to now.
Non-technology driven levers for management
On top of better technology and engineering, O&G companies needs to look at all the levers they have to improve the productivity of their assets & people
It has become standard practice to plan wells and analyze bit performance using log-based rock strength analysis and/or specific energy theory. The most widely used characterization of rock strength is unconfined compressive strength (UCS), but this is somewhat problematic because the "apparent" strength of the rock to the bit is typically different than UCS. There is awareness of this problem, but to date there is not an industry standard or widely used methodology to address it. Specific energy theory has been used for bit performance assessment for years. One of the challenges of application of the specific energy theory, however, is uncertainty or lack of consistency in reasonable values for the input variables.
Globally applicable solutions and methods to address these problems have been developed and implemented by ChevronTexaco. A new method to calculate rock confined compressive strength (CCS), based on both conventional and somewhat innovative rock mechanics principles has been developed. A new method to determine input variables for bit performance prediction based on specific energy theory and CCS has been developed. These have been integrated to provide new capability for rapid and accurate determination of expected or achievable rate of penetration and operating parameters for all bit types. The new models have proved valuable, improving drilling performance and reducing well cost by improving bit performance prediction, bit selection, and determination of optimum drilling parameters. The methods are robust, based on fundamental and/or first principles, require little or no calibration, and any required calibration is intuitive and simple. Presented are background, theory, research results, the new methodologies, and field and lab data which validate and illustrate the methods.
During the late 1990's, Chevron Exploration and Production Technology Company (EPTC) initiated work on a project to with the objective to improve pre-drill and drilling performance prediction based on a mechanical earth model (MEM). The required components of this project were:
Ji, Yuanyuan (Beijing Research Institute of Chemical Industry, China Petroleum & Chemical Corporation) | Yang, Yuanyi (Beijing Research Institute of Chemical Industry, China Petroleum & Chemical Corporation)
Naphtha was steamcracked over ZSM-5 zeolites modified by both calcium and magnesium cations in a fixed-bed quartz reactor. Calcium and magnesium cations with a constant proportion were simultaneously impregnated into the fresh ZSM-5 zeolite with Si/Al ratio 140 (mol/mol). After drying and calcination, the modified zeolites were ground into 20~40 mesh for use. Reaction conditions were: temperature 700°c, W/O (w/w) =1.1, WHSV 12h-1.
It was found that Si/Al ratios of the modified ZSM-5 zeolites incresed with the decrease of the impregnated metal contents. And all modified zeolites had higher Si/Al ratios than the fresh one. The total acid amounts of the modified zeolites raised with the Si/Al ratios when the Si/Al ratios were less than 200.86, then dropping and rising again. However, B/L values had no obvious tendency with Si/Al ratios of the modified zeolites.
It was also found that gas yields and C2=+ C3=+ C4== yields basically went up with the increase of Si/Al ratios of the modified zeolites. And a maxium also appeared when the Si/Al ratio was 200.86. Meanwhile, it was found that BTX yields basically raised with the gas yields except the Si/Al ratio with 200.86, when a minimum was seen.
In addition, it was found a distinct difference of C5+ product distributions between the modified zoelites and the fresh one. Obviously, the diffenrence was an appearance of the modified function on the steam cracking.
As above, it was obtained a direction to the preparation of modified ZSM-5 zeolites with Ca and Mg through the comparison of the characterization results with the steamcracking ones. Also it was acqiured the modification function of the Ca and Mg on the ZSM-5.
Naphtha steamcracking is an important way to produce ethylene now. Due to the increasing need to propylene, the catalytic steamcracking naphtha has been developed. Usually, the catalysts are focused on the modified MFI zeolites. And the objective of the modification is to change the acidic properties of the original zeolites. In the paper, double alkali-earth metals, calcium and magnesium, were used to modify the ZSM-5 zeolite.
Preparation of catalysts
The original ZSM-5 zeolite, with Si/Al ratio 140 (mol/mol), was produced by Hunan Jianchang Petrochemical Co., Ltd, China, and marked as ZRP140. The original zeolites were modified by a series of calcium and magnesium elements, with a certain proportion, through ion-exchange+immersion. After drying and calcination, the modified zeolites were ground into 20~40 mesh.
Analysis of products
The industrial naphtha was provided by Yanshan Chemical Industrial Factory, SINOPEC. The tail gas was routinely analyzed by GC. The liquid products and Yanshan naphtha were qualitatively and quantitatively analyzed by GC-MS. The components of Yanshan naphtha were listed as Table 1.
(Table in full paper)
Catalytic steamcracking of naphtha
The catalytic steamcracking of naphtha was performed in a quartz reactor. The catalyst loading was 1g, reaction temperature 700°C, water/oil (w/w) 1.1, WHSV 12h-1.