bluuebunny/crossref_metadata_2025 huggingface dataset:
Successful Horizontal Drilling and Gravel Packing in Deep and Ultra-Deepwater
Authors: Vozniak J. P. , Mathis S. P. , Hogg W. C. , Ratterman E. E.
Published: December 2007

This paper discusses specialized completion tools and techniques developed while drilling and completing the open hole sections of 20 horizontal gravel packs and 3 Level 5 multi-lateral wells completed in Campos Basin, offshore Brazil. The discussion covers wellpath planning, pumping operations, wellpath selection, multilterals, the use of extended-longevity well screens, floating rig operations, and fluid systems to prevent formation damage.

Open hole horizontal wells are attractive in ultra-deep water because the approach eliminates a liner and allows a larger casing string at the reservoir. This method also provides extensive reservoir exposure. Couple this technology with multi-laterals and a significant reduction in the number of wells to adequately drain the reservoir may be achieved.

Twenty open hole completions have been successfully performed in the deepwater Marlim field offshore Brazil. These include both gravel- and non-gravel-packed completions in horizontal producers and injectors. Additionally, three Level 5 multi-lateral wells with open hole completions have been successfully installed in the same field.

Multi-lateral (ML) completions have been classified as Levels 1 through 6, depending upon junction functionality. Only Levels 5 and 6 pertain to this discussion. Only Levels 5 and 6 provide pressure integrity at the junction. Level 5, a cased and cemented main bore and laterals, achieves pressure isolation at the junction with packers. Level 6 is similar to Level 5 except that pressure isolation at the junction is achieved using the casing.
A New Method Of Determining Range And Direction From A Relief Well To A Blowout Well
Authors: Morris F.J. , Waters R.L. , Roberts G.F. , Costa J.P.
Published: December 2007

A method utilizing four component-type magnetic sensors for the determination of range and direction from a relief well to a blowout well is presented. The advantages of using component-type magnetometers and magnetic gradient information are enumerated. The equipment and its operation are described. Typical examples of results obtained in field operations are given and their analysis is discussed.

Introduction

There are few events more frightening than a fiery catastrophic blowout on an offshore drilling platform. In an astonishingly short time the rig disintegrates and sinks onto the ocean floor, leaving only a huge gas bubble boiling through the water's surface. If the escaping gas does not continue to burn, it is generally ignited for safety. Onshore blowouts can be equally devastating, particularly if the surface conductor is not particularly if the surface conductor is not accessible. Under either of these circumstances the most successful way to bring the blowout well under control is to drill a relief well directed so as to intersect the blowout well, or to get sufficiently close to the blowout well at the problem area so that fluid communication between the two wells can be effected. Thereafter the kill attempt can be accomplished and the blowing well brought under control. See Figure 1.

As simple as this procedure may appear, the exact location of the relief well and the blowout well at depth are seldom known with sufficient accuracy to assure an effective kill operation. The principal reason for this is that well surveys are typically made with precisions no greater than a quarter of a degree. At a depth of 10,000 feet this means that each well may be anywhere within a circle of 87 feet diameter. Furthermore, additional cumulative deviations can occur in both wells which would substantially increase the areas of these circles of uncertainty. In the worst case, the two wells may be too far apart to establish communication by any reasonable means. In the critical situation of attempting to control a blowout well, the range and direction from the relief well to the blowout well must be known.

In late 1975, Houston Oil and Minerals Corporation commissioned Tensor to develop a system for making such measurements.

P. 1
Formation and Control of the Vaterite Scale Polymorph of Calcium Carbonate in the Galley Field Development
Authors: Brankling D. , Bayman M. , Jenvey N.
Published: December 2007

Producing wells in the North Sea Galley Field development require application of scale inhibitor at the sub-sea wellheads to prevent formation of calcium carbonate scale across the sub-sea chokes. The wells tie back to the Northern Producer Floating Process Facility (FPF) through rigid carbon steel flowlines which also require chemical inhibitor application to control corrosion. Historically a combined scale / corrosion inhibitor has been applied to provide the necessary scale and corrosion protection downstream from this point in the production process. Following a series of process upsets which occurred in 1999 due to topsides scale formation, the vaterite polymorph of calcium carbonate was identified as the primary scaling species produced in the process system, with subsequent research showing that vaterite formation was induced by the use of corrosion inhibitor in the process stream. This paper presents information on the stabilisation of the normally metastable vaterite polymorph of calcium carbonate and questions the common perception of direct scale inhibitor / corrosion inhibitor incompatibility as a primary factor in reduced inhibitor performance.
Scale Potential of a Deep Water Field - Water Characterisation and Scaling Assessment
Authors: Rosario F. F. , Bezerra M. C. M.
Published: December 2007

This paper presents the methodology for characterisation (sampling and analysis) of formation water and scale prediction in the waterflooding project of a deep-water field, from Campos Basin, Brazil. A subsea well A, representative from an oil-producing sandstone reservoir of this field was selected for sampling. Bottom-hole sample was taken in the open hole well at the oil-water contact using a modular formation dynamics tester – MDT. After completion operations, both wellhead and bottom-hole samples (positive displacement sampling – PDS) were collected in the aquifer zone.

The gas from the bottom-hole samples was analysed using chromatography. Bicarbonate determination was performed at offshore laboratory using a controlled microprocessing titration.

As the water sample at the oil-water contact was similar to the composition of the aquifer, it was used to predict the scaling potential in the field. Two models were considered for prediction: the thermodynamic model OKSCALE and the geochemical code GWB. These models predict the precipitated mass and calculate the saturation index (SI) of the most common scales in an oilfield during waterflood operations (BaSO4, SrSO4, CaSO4 and CaCO3). The mass and SI of the insoluble compounds were calculated for the various injection and formation water mixture ratios, occurring over the field life. Precipitation of barium sulphate and strontium sulphate was found to be likely at produced wells (downhole and flow lines) and surface facilities.
Factors Influencing Sulphide Scale Generation Associated with Waterflood Induced Reservoir Souring
Authors: Evans Robin
Published: December 2007

Iron sulphide scale can be deposited in production tubing, topsides facilities due to reservoir souring associated with water injection. One of the main mechanisms of reservoir souring is believed to be the reduction of sulphate in the injected water by sulphate reducing bacteria (SRB). To be active in the reservoir, the SRB need to be able to utilize fatty acids, which are present in the formation water, often in the cooled region of the reservoir in the vicinity of the water injection well. Consequently the location and the degree of mixing of the injected water with the in-situ brines in the oil zone and the water zone is a significant factor in the potential for reservoir souring and subsequent iron sulphide scale generation.

Brine mixing occurs to very different extents, depending on the reservoir geometry and on the presence or absence of an aquifer (water zone). When water injection is into the oil zone, banking of the connate water occurs ahead of the injected water, resulting in limited mixing of the two waters in the reservoir. When water injection is into the water zone (aquifer), the degree of water mixing is much greater, increasing the potential for biogenic reservir souring.

Based on the above discussion, water injection into the aquifer should result in a greater degree of reservoir souring than injection into the oil zone. For water injection into the oil zone water mixing in the reservoir is restricted and biogenic sulphate reduction may be delayed until the waters mix in the production facilities.
Soap-Oil Systems For Formation Fracturing
Authors: Hendrickson A.R. , Nesbitt L.E. , Oakes B.D.
Published: December 2007

One of the important characteristics of a fluid is its viscosity, since this is closely associated with its sand-carrying ability. From the standpoint of economy it is sometimes more advantageous to thicken a non-viscous petroleum fluid, than to use a more expensive, naturally viscous oil.

This paper discusses the use of certain alkali metal, oil-soluble soaps in. non-polar solvents, such as kerosene, diesel fuel, and crude oil. By in situ neutralization of long chain aliphatic organic acids, in a hydrocarbon media, a sodium-soap dispersion is obtained. Such soaps produce micelles, the aggregation of which results in low fluid loss and low sand-falling rates. Also, the fluid exhibits thixotropic properties, providing additional sand support without a corresponding increase in the true or Newtonian viscosity.

This paper describes the characteristics of the micellular aggregations, their formation and properties. The relationship between the apparent and true viscosities of such dispersions is shown. The effect of brine on these soap-oil systems is also discussed.

Introduction

Oil-dispersible alkali metal soaps have been familiar industrial compounds for several years; they have found many uses in various fields. Because of their unique colloidal nature in nonaqueous solvents, their use has been recently extended to formation fracturing for primary recovery of well fluids. This paper will discuss some of the aspects and properties of certain alkali metal oil-soluble soaps in non-polar solvents such as kerosene, diesel fuel, and crude oil.

Many improvements have been made in materials and techniques of application, since the introduction of hydraulic fracturing as a method of stimulating production from oil and gas wells. A variety of fluids have been employed to open fractures and carry propping agents, among which are gels, emulsions, and refined oils. Developments made during the last few years have included modifications of these fluids in order to overcome and eliminate certain difficulties that were encountered in field applications.

The most recent general development in fracturing fluids has been a soap-oil dispersion that combines the best features of other fracturing fluids and overcomes many of their disadvantages. The familiar phenomenon of mice the formation of soaps in aqueous solutions also occurs in nonaqueous media. This was demonstrated by Reuggerberg and other workers in this field. By in situ neutralization of long chain aliphatic organic acids in hydrocarbons, a sodium soap dispersion can be obtained that is a satisfactory fluid for fracturing.
Application: Monte Carlo Simulation in Risk Evaluation of E&P Projects
Authors: Komlosi Zsolt P.
Published: December 2007

The three basic types of risks for projects are market risk, country/political risk and business risk. While the former and the latter should be evaluated simultaneously, the country risk is applied with a special opportunity cost (discount rate) weighted with a country risk factor.

The basis of risk evaluation is the net present value calculated with a cash flow model showing the breakdown in discounted differences of all future costs and revenues throughout on entire project. The simulation model will be programmed to handle the main incoming data, which define the market and business risk (e.g., oil price, inflation, foreign exchange, reserves, ultimate recovery, specific costs, taxes and similar payables, etc.) as stochastic variables.

For defining the distribution functions as variables that reflect market risks, the basis will be the variance of values in the past and the expected figures planned in the company's premises. Some parameters are not independent (e.g., under identical circumstances lower unit costs are associated with larger reserves), therefore analysts can define a correlation between the specific parameters by historical data Those co-efficient will be applied by the utilised software during the simulation.

After running all the cycles a frequency function is compiled from the results and this will serve as the basis for defining data relating to cash flow (e.g., expected value, standard deviation, values relating to 5% or other cumulative frequency, etc.). The main indicator (borrowed from the field of financial risk management) is Value at Risk (VaR) which is the difference of the expected NPV and the NPV value at, generally, 5% cumulative frequency. Another important index is the Reward per Risk ratio of expected NPV and VaR.
Return on Investment in Energy Education
Authors: Tobin John C.
Published: December 2007

The paper discusses the very nebulous nature of measuring the ROI on energy education. However, it suggests that such returns are measurable in terms of an improved (more certain) business environment that would be realized with an informed (energy literate) public.

In K-12 alone there is very real demand for balanced educational programs in energy. Specifically, in spite of the lack of curriculum requirements to cover the topic, teachers are requesting educational material that meets national and local educational standards by demonstrating "good science", alternatives and cost/benefit analysis. Educators recognize that the energy theme is a great way to teach history, geography, economics, earth sciences and social sciences, etc.

The industry is asked if it will not meet this real demand for balanced energy education, who will? Education is the foundation that leads to a public that understands the importance of energy in its economic well being and in its quality of life. Such an informed public will then allow for a more stable and rational business environment for the industry. Is the industry willing to bypass this investment opportunity?
Characterizing Uncertainty in Oil and Gas Evaluations
Authors: Caldwell Robert H. , Heather David I.
Published: December 2007

The past 10 to 15 years have seen a major shift in thinking on the subject of uncertainty and its incorporation into oil and gas evaluations. Witness the struggle that has occurred in the adoption of probabilistic expressions of reserves estimates and the gradual acceptance of these methods by the industry. Despite this new-found acceptance, there is still much confusion on how such evaluations are performed (lack of consistent ground rules or calibration procedures) and particularly, how to use or interpret the results. The question then becomes, have we really made any progress in terms of improving the accuracy of our estimates?

This paper explores the sources of uncertainty in an oil and gas evaluation and attempts to characterize these sources by their definition and interrelationships in order to better understand how to handle them. As geoscientists and engineers, we tend to focus on generally simple computational procedures to calculate most of our required parameters. In other words, we fit a straight line through the scatter to develop a transform, calculate a result, and move on. Many empirical relationships are in standard use that were developed from very scattered data. Such methods have changed little as graph paper gave way to hand calculators, and now computers.

In characterizing uncertainty, we document the sources as including measurement inaccuracy, computational approximation, the effect of incomplete or missing data and dealing with naturally stochastic systems, and examine the impacts on the evaluation of uncertainty. Finally, comparisons are made with non-oilfield handling of uncertainty to compare and contrast concepts and the way we visualize the results.

Does this improve the accuracy of our evaluations? Read on, you will be surprised at the answer.
Predicting Natural Gas Production Using Artificial Neural Network
Authors: Al-Fattah S. M. , Startzman R. A.
Published: December 2007

The industrial and residential market for natural gas produced in the United States has become increasingly significant. Within the past ten years the wellhead value of produced natural gas has rivaled and sometimes exceeded the value of crude oil. Forecasting natural gas supply is an economically important and challenging endeavor. This paper presents a new approach to predict natural gas production for the United States using an artificial neural network.

We developed a neural network model to forecast U.S. natural gas supply to the Year 2020. Our results indicate that the U.S. will maintain its 1999 production of natural gas to 2001 after which production starts increasing. The network model indicates that natural gas production will increase during the period 2002 to 2012 on average rate of 0.5%/yr. This increase rate will more than double for the period 2013 to 2020.

The neural network was developed with an initial large pool of input parameters. The input pool included exploratory, drilling, production, and econometric data. Preprocessing the input data involved normalization and functional transformation. Dimension reduction techniques and sensitivity analysis of input variables were used to reduce redundant and unimportant input parameters, and to simplify the neural network. The remaining input parameters of the reduced neural network included data of gas exploratory wells, oil/gas exploratory wells, oil exploratory wells, gas depletion rate, proved reserves, gas wellhead prices, and growth rate of gross domestic product. The three-layer neural network was successfully trained with yearly data starting from 1950 to 1989 using the quick-propagation learning algorithm. The target output of the neural network is the production rate of natural gas. The agreement between predicted and actual production rates was excellent. A test set, not used to train the network and containing data from 1990 to 1998, was used to verify and validate the network performance for prediction. Analysis of the test results shows that the neural network approach provides an excellent match of actual gas production data. An econometric approach, called stochastic modeling or time series analysis, was used to develop forecasting models for the neural network input parameters. A comparison of forecasts between this study and other forecast is presented.

The neural network model has use as a short-term as well as a long-term predictive tool of natural gas supply. The model can also be used to examine quantitatively the effects of the various physical and economic factors on futuregas production.
Using Crosswell Electromagnetics to Map Water Saturation and Formation Structure at Lost Hills
Authors: Wilt Mike , Zhang Ping , Morea Mike , Julander Dale , Mock Paul
Published: December 2007

In 1992, Chevron USA initiated a large waterflood program in the Belridge Diatomite at Lost Hills Field. Injection and production wells are hydraulically propped-fractured, and water is injected across a vertical interval of approximately 600 ft. The injected water is assumed to follow the hydraulic fractures and spread laterally outward. However, the extent of flooding, the saturation variations between individual layers, and the connection between waterflood patterns are poorly understood.

During this same time period, crosswell electromagnetic technology was developed and tested in other fields in the San Joaquin Valley. This technology can provide an interwell resistivity distribution from wells separated by up to 1000 ft, and thus, may be suitable for mapping water saturation variation and reservoir structure.

In this paper we describe the application of crosswell EM technology to several waterflood patterns at Lost Hills. The first cases involve surveys between closely spaced fiberglass-cased observation wells across and perpendicular to a hydraulic fracture. The interwell resistivity distribution identified the edge of the waterflooded region and mapped saturation variation between the layers that were affected by the flood. In another example, crosswell data that were collected parallel to hydraulic fracture planes show the connection of injection plumes and also significant saturation variation between layers
Ternary Diagram To Visualize Well Intervention Opportunities for Production Improvement - A Case History in Cusiana Field, Colombia.
Authors: Prada A. , Lazaro G. E. , Gonzalez F. A. , Carrillo L. F. , Osorio A. M.
Published: December 2007

Ternary diagrams have been used mainly in chemistry applications, and in geology for characterizing mineral components of rocks. In this study the ternary diagram called the Cusiana Well Performance Triangle is being proposed as a powerful well - reservoir surveillance evaluation tool. The main contribution of this diagram is to provide well surveillance engineers and managers with a tool that facilitates the decision making process.

Decline in productivity is influenced by reservoir related factors such as fluid properties, rock properties, pressure depletion trend, GOR and WOR increase trends and physical skin build up, generated by different methods. Usually organic substances, inorganic scales or very fine materials are transported and/or deposited in thenear wellbore region, hence, high decline rates can be observed.

In this study a well performance analysis and a formation damage evaluation were conducted using nodal analysis. The final delivery was the quantitative contribution of the main factors influencing the well productivity. The results are presented graphically in the ternary diagram referred to as Cusiana well Performance triangle.

The position of a well in the triangle indicates the factors that are influencing well performance. The triangle is used as a first step in understanding well performance with a view to wellwork candidate selection.

Recommendations based upon the observed results can provide the operator with a reliable tool to implement a formation damage management strategy for the Cusiana field.
Development and Application of a Dual-Parameter Instrument for Steam Two Phase Flow
Authors: Dai Peiwen , Wu Guowei , Wang Zuoqing , Zhang Yi
Published: December 2007

Though theoretical and experimental study, This program create a method which makes use of pulsating characteristic of the water and steam two-phase flow to measure both steam flow rate and quality parameters. Using only a restriction device (orifice), online measures simultaneously on steam flow rate and quality are achieved by measuring different pressure and its corresponding pulsating value.

According this method, a two-phase flow instrument has been developed, which is with simple structure and easy to operate. The measuring mean square errors of both flow rate and quality are less than 5% in the pressure range 2-16Mpa, flow rate 1-16t/h and quality 0-100%.

The instrument has been distributed over 430 sets in Shengli, Xinjiang, Henan and Neimeng Erlian Oil Field.
Geothermal Reservoir Modelling
Authors: Coats K.H.
Published: December 2007

This paper describes and partially evaluates an implicit, three-dimensional geothermal reservoir simulation model. The evaluation emphasizes stability or time-step tolerance of the implicit finite-difference formulation. In several illustrative multiphase flow problems, the model stably accommodated time steps corresponding to grid block saturation changes of 80–100% and grid block throughput ratios the order of 10(8). This compares to our experience of limits of 3 to 10% saturation change and roughly 20,000 throughput ratio with semi-implicit oil and geothermal reservoir models.

The illustrative applications shed some light on practical aspects of geothermal reservoir behavior. Applications include single- and two-phase single-well behavior, fractured-matrix reservoir performance and well test interpretation, and extraction of energy from fractured hot dry rock. Model stability allows inclusion of formation fractures and wellbores as grid blocks.

An analytical derivation is presented for a well deliverability reduction factor which can be used in simulations using large grid blocks. The factor accounts for reduced deliverability due to hot water flashing and steam expansion accompanying pressure decline near the well.

This paper describes a numerical model for simulating geothermal well or reservoir performance. The model is considerably more performance. The model is considerably more general than any described in the literature to date. It treats transient, three-dimensional, single- or two-phase fluid flow in normal heterogeneous or fractured-matrix formations. Both conductive and convective heat flow are accounted for and fluid states in the reservoir can range from undersaturated liquid to two-phase steam-water mixtures to superheated steam. Aquifer water influx and heat source/sink terms necessary in simulating free convection cells are included in the model formulation.

The primary purpose of the work described here was evaluation of the capability of an implicit model formulation. our experience with semi-implicit simulation of petroleum and geothermal reservoirs has shown time step restrictions related to conditional stability. In multiphase flow problems, the maximum tolerable time step size generally corresponds to a maximum of 3 to 10 percent saturation change in any grid block in one time step. In some steamflood and geothermal simulations, we have found this to result in very small time steps and correspondingly high computing costs. This work was performed with the hope that the implicit model formulation would give unconditional stability with no time step restriction other than that imposed by time truncation error.

Calculated results are presented for a variety of geothermal well and reservoir illustrative problems. Emphasis in connection with these results is placed on the stability or time step tolerance of the model. However, the applications are also intended to shed some light on practical aspects of geothermal reservoir practical aspects of geothermal reservoir behavior.
Policy Implications of Locating Energy Development Facilities in the Rocky Mountain Region
Authors: Smith Michael D. , Ielinek Dwayne
Published: December 2007

This paper addresses characteristics of Rocky Mountain regional energy development and focuses upon the policy positions taken by affected states in handling social and economic impact. The standardizing influence of the National Environmental Protection Act has eliminated many regional differences in the way companies deal with the environmental aspect of their energy development planning. However, within the general environmental impact category, social and economic impacts have not been adequately dealt with in the past. This is true for two reasons: first, past. This is true for two reasons: first, the precedent or body of knowledge associated with impact assessment of social and economic changes has been poorly developed; and second, the required economic theory needed to approach the problems has not been applied. In a sense, with regard to the theory of regional development economics when applied to western energy areas, we are dealing with the same or similar problem that underdeveloped countries face during periods of rapid development. In order to get an economic sense of the problem and to introduce the corrective or mitigating measures taken, this paper will cover the problem background, the development process, problem background, the development process, rapid regional growth process, impact analysis, impact control and, finally, a potential state planning role.

The central thesis is that, without planning, the region will probably reach planning, the region will probably reach economic equilibrium with severe local economic dislocations. However, with appropriate planning, even to the point of managing the state's economy, national energy expectations from the Rocky Mountains can be achieved and the region can prosper.

Introduction

" The whole is the synergistic sum of its parts" is an appropriate focus for parts" is an appropriate focus for understanding the dynamics of a national economy. However, thinking regional has not received the level of attention commensurate with regional roles in the determination of national income and companion social welfare. The question of thinking regional, with regard to energy and mineral development in the Unites States or in any Country, is one of recognizing national economic implications while focusing upon the economic impacts of regional development.
The Mixed and Vexed Subject of Oil Industry Profits
Authors: Johnson William A.
Published: December 2007

The U.S. oil industry has come under widespread criticism for having earned excessive profits. Partly for this reason, the industry has also been subjected to increasing regulation by the federal government. It is widely thought that the industry's profits reflect the monopoly power of U.S. oil companies and that freeing U.S. producers from price controls would only producers from price controls would only allow them to share in additional extraordinary profits now being earned by OPEC. In fact, federal controls have denied to U.S. producers part of their "producers' surplus," the rewards they have earned for having pioneered new ways of doing business, taken extraordinary risks successfully, minimized their costs of production, and, perhaps most important, chosen, in the past, perhaps most important, chosen, in the past, to focus their investment in exploration and production in the United States and not production in the United States and not abroad. As a result, these controls are, in various ways, discouraging output of oil by U.S. companies and encouraging unnecessary demand by U.S. consumers. This is, in turn, increasing U.S. dependence on imported oil primarily from OPEC. primarily from OPEC

Introduction

In 1895, the American economist, Frank Taussig, declared profits to be "that mixed and vexed income" after surveying what had been written on the subject by the learned men of his profession. This description is equally appropriate today, especially when describing the current controversy over oil industry profits. The industry's profits have been condemned by one senator as "unconscionable" and by another as "obscene". Partly because of their alleged profiteering, Partly because of their alleged profiteering, the major oil companies have been called such names as "robber barons" and "unfeeling monopolists' in the press.

What is at issue are abnormal profits in excess of the basic minimum level of payment to management or return to capital payment to management or return to capital necessary to keep a company in business. Economists have identified many reasons for abnormal profits—some bad, some good— and it is this that has made profits a "mixed and vexed" subject in both Taussig's and our times. Abnormal profits may reflect the presence of monopoly or an "unearned presence of monopoly or an "unearned increment" accruing to a landlord. Or abnormal profits may reward a businessman for profits may reward a businessman for extraordinary performance and successful innovation and risk-taking.
Use of a Fullbore-Access Level 3 Multilateral Junction in the Orinoco Heavy Oil Belt, Venezuela
Authors: Smith K. M. , Rohleder S. A. , Redrup J. P.
Published: December 2007

Petrozuata C.A. has initiated an aggressive campaign of constructing multilateral wells in their shallow extra-heavy-oil field in the Faja of the Orinoco River, Venezuela. The RapidTieBack* multilateral drilling and completion system has been used on many of the multilaterals.1 The system uses a casing section, with a factory-milled window, that is run in the 9 5/8-in. production casing string. Lateral 8 1/2-in. boreholes are drilled from the 9 5/8-in. casing and fitted with 7-in. slotted liners. The system employs a liner tieback on the top of the 7-in. liner. The liner tieback is mechanically pressed into the window. The tieback creates a fullbore TAML Level 3 (lateral cased, uncemented) junction. The fullbore access within the 9 5/8-in. production casing allows placement of a progressive cavity pump (PCP) below the junction(s) and thus closer to the lowest lateral. The system utilizes a production whipstock to allow selective reentry into any lateral.

The benefits of utilizing this system and a general description of the running procedures are presented in this paper. Some of the problems are described as well as the changes to the procedures that helped prevent reoccurrence of the problems.
Formation Damage Control Utilizing Composite-Bridge-Plug Technology for Monobore, Multizone Stimulation Operations
Authors: Garfield Garry
Published: December 2007

Composite bridge plugs (CBPs) save operator time and money by enabling quick and easy installation and removal. CBPs can be installed under pressure in multi-zone, commingled gas wells without using expensive formation kill weight fluids. Kill weight fluids can reduce production from the well, and in some cases have damaged newly fractured zones to the extent that production has been cut in half.

After remedial operations, CBPs can be removed using coiled- tubing-conveyed milling equipment in one fourth of the time required to mill traditional cast iron bridge plugs. Formation damage can be substantially reduced using low viscosity milling fluids that easily remove composite cuttings from the wellbore. This is especially important because of the low annular velocities characteristic of coiled tubing operations. The wellbore is left cleaner than those using cast iron bridge plugs in similar operations.

CBPs can withstand high pressures for up to 10 days without compromising their pressure integrity and without the need for a cement barrier on top of the CBP. Initial field runs have demonstrated that the CBPs can be milled as quickly as 30 minutes compared to 2 hours for milling conventional cast iron bridge plugs. Multi-zone, commingled gas wells using as many as 7 CBPs have been brought back on production after taking only 12 hours to remove all CBPs, including rig-up and rig- down of the coiled tubing unit. Field runs also indicate CBPs can be milled quickly when set at depths exceeding 19,000 feet.
Estimating Bulk Volume Oil in Thin-Bedded Turbidites
Authors: Weiss W. W. , Stubbs B. A. , Balch R. S.
Published: December 2007

Determining the water saturations in thin-bedded turbidites using wire-line logs is difficult; errors in Sw calculation frequently result in uneconomical completions. Consequently, current Brushy Canyon completion decisions include expensive core information to provide an acceptable indicator of oil saturation in order to compensate for the Sw calculation problem. Completion decisions can be improved and less core data is needed using a new method that correlates wire-line logs with core measured bulk volume oil (ΦSo).

A neural network was trained and tested using density and neutron porosity plus shallow and deep resistivity logs as input variables. The neural network was trained to predict the ΦSo product from whole core analysis.

The trained and tested neural network was then used to estimate ΦSo in 25 additional Brushy Canyon wells that were not used in the training, but had the same four wire-line logs. A ΦSo cutoff of 22 units was determined and values greater than the cutoff were summed through the perforated interval in each well. The summed bulk volume oil of the 25 wells was plotted versus the first year’s total production. The plot suggests that ΣΦSo greater than 20,000 units will usually result in an economical new well or reentry completion.

During the course of optimizing the neural network architecture, valuable insights into network architecture design were gained. For this type of study, less complex architectures produced robust testing results, indicating that the solution, though non-linear, is still reasonably simple.

The method should be useful when evaluating behindpipe completion opportunities in the Brushy Canyon interval of the Delaware Sands in the Permian Basin. Re-completion costs are lower than new well costs; thus thin zones with high values of ΦSo are potential targets.
A Full Field Simulation Model of the Minagish Oolite Reservoir in Kuwait
Authors: AL-Mutairi Saad , AL-Medhadi Fahad , AL-Ajmi Hamad , Meadows David , Oosthuizen Ulrich R.
Published: December 2007

The Minagish Oolite is a thick undersaturated carbonate oil reservoir in the Minagish field in West Kuwait (Fig. 1) containing several billion STB. It is a mature but relatively undeveloped reservoir. Since discovery in 1959, it has produced 10% of its OOIP under a combination of natural depletion, gas re-injection and aquifer drive. Initial reservoir pressure had declined by about 450 psi prior to the Gulf war in 1990. The well blowouts following the war caused a significant pressure drop of another 700 psi. Following the blowout, plans were made to redevelop the West Kuwait fields and increase the production rate starting in 2001 and to sustain the plateau for at least 5 years. This strategy called for three-fold increase in the production rate of Minagish Oolite reservoir. Since the existing well inventory and the loss of the gas re-injection facility could not sustain the desired plateau rate, additional field development was required.

To achieve the production target, a multidisciplinary team was formed to evaluate options. The recommended plan required the drilling of additional producers and installing a field-wide peripheral waterflood. The reservoir, however, presented a number of significant challenges to waterflooding, such as the presence of a substantial and not well defined tarmat near the oil/water contact, and uncertainties of lateral and vertical heterogeneities. In 1997 a full-field simulation model was developed, but this model didn’t capture the water movement properly because of insufficient reservoir data at that time. As new core was obtained, a refined reservoir description was developed. Building on lessons learned from the previous full-field model and sector models, a new full-field model was developed which significantly improved well-by-well history matches. Although containing twice as many grid cells, the new model ran up to four times faster than the previous model by making use of the Analytical Aquifer option within the model, improved relative permeability curves and other model refinements.

This paper traces the history of the field and the systematic evolution of the development plan. The reservoir simulation efforts including modeling strategy, history matching events, prediction runs, future direction and challenges are also addressed.
A Mlcroscoplc Study Of The Effect Of Variable Wettability Conditions On Immiscible Fluid Displacement
Authors: Morris Earl E. , Wieland Denton R.
Published: December 2007

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This paper is to be presented at the 38th Annual Fall Meeting of the Society of Petroleum Engineers of AIME in New Orleans, La., on October 6–9, 1963, and is considered the property of the Society of Petroleum Engineers. Permission to publish is hereby restricted to an abstract of not more than 300 words, with no illustrations, unless the paper is specifically released to the press by the Editor of the JOURNAL OF PETROLEUM TECHNOLOGY or the Executive Secretary. Such abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or SOCIETY OF PETROLEUM ENGINEERS JOURNAL is granted on request, providing proper credit is given that publication and the original presentation of the paper.

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This paper presents the results of a microscopic investigation of immiscible fluid behavior under variable wettability conditions. Seventeen waterfloods were conducted in a monolayer glass-bead flow cell under water-wet neutral-wettability, oil-wet, and wettability-reversal conditions.

Quantitative production data were obtained for each flood. Also, a 16 mm film recording utilizing an arriflex camera was made during each flood test. Photographs taken from 16 mm film recordings are herein presented as being representative of the microscopic and macroscopic behavior for the fluid systems studied.

Residual oil structures were visually defined as being noncontinuous under water-wet conditions. Oil-wet conditions yielded both continuous and noncontinuous type structures. The idea of residual oil continuity under oil-wet conditions is proposed as being responsible for increased oil production when going from an oil-wet to a water-wet condition. In all cases during these experiments where additional oil was recovered during a reversal flood, there was essentially continuity of the residual oil saturation following the conventional waterflood under oil-wet conditions.

It has been shown that, where residual oil continuity existed, oil mobility may be established from a transient change in contact angle. An attempt has been made to define the mechanism responsible for this phenomena.

Introduction

The recovery of additional oil from a reservoir following primary depletion can be achieved only by the application of energy from external sources such as the introduction of heat and/or kinetic energy of other fluids. A process which supplies this additional energy is called a secondary recovery process. Unfortunately, present secondary recovery methods, which are economical, still leave up to 40 per cent of the reservoir's original oil content trapped by capillary and hydrodynamic forces.
Cost-Effective Recompletions of Fruitland Formation Coalbed Methane Gas Wells are Achieved With PDC Technology-Based One-Trip Sidetracking and Lateral-Drilling Technique
Authors: Nye Bruce , Reid Dave , Childers Ronald D. , Miller Gregory C. , Sanchez Eppie
Published: December 2007

Sidetracking mills designed with PDC insert cutting structures were able to effectively mill a casing window and drill the required lateral in one trip. This new application of advanced PDC technology in Fruitland Formation coalbed methane gas wells provides cost and timesaving benefits. This progressive effort by the operator to improve efficiency and to optimize the recompletion procedures for San Juan Basin wells is furthering exploitation of hydrocarbon reservoirs.

This paper discusses how mills designed with PDC inserts swiftly cut steel and drill formation to produce a lateral well bore from the mother bore. The technique reduces the number of trips, equipment, costs, and time required to recomplete the well. The operator is able to minimize loss of production on a downed well by getting the well back on-line sooner.

Three case histories are presented that illustrate how this new technology and technique were first applied in the San Juan Basin and further developed through their utilization to recomplete coalbed methane gas wells.
Flow-Induced Stress Reorientation in a Multiple-Well Reservoir
Authors: Hidayati Dewi Triarti , Chen Her-Yuan , Teufel Lawrence W.
Published: December 2007

Flow-induced stress change causes redistribution of stresses in reservoirs which can lead to reorientation of principal stresses. Stress reorientation has direct impact on fracture orientation and thus drainage or flood pattern. Consequently, drainage or flood pattern after certain time of production/injection may be different from the original expected pattern. Stress reorientation in a multiple-well reservoir is studied to determine the controlling parameters. An analytical-based, coupled fluid-stress model is adopted for this study. Multiple wells and variable flow rates are handled by the principle of superposition. Result shows that flow-induced stress change can cause principal stress direction to undergo from gradual to sudden reorientation, or to remain unchanged. Their occurrences are time and space dependent, and determined by initial stress anisotropy, permeability anisotropy, flow mode (injection/production), and flow rate. Well interference is also identified as an important factor affecting stress reorientation. Examples of application using stress trajectories to infer fracture orientations are presented.
Environmental Aspects Of Enhanced Oil Recovery
Authors: Scott Robert M. , Zwicker Stanley L. , Jonker Peter E.
Published: December 2007

Introduction

The future application of enhanced oil recovery (EOR) technologies will undergo a very complex governmental approval process. Reviews will be conducted in the areas of air quality, water quality, protection of drinking water, toxic substances, and solid or hazardous waste management. As a result of these reviews, projects involving new technologies or the expanded use of existing technologies may face significant delays.

This paper traces the oil industry's permitting problems in California through the labyrinth of federal and state laws and regulations. Analysis of the role these environmental constraints may play in future EOR projects is also attempted.

On the impetus of federal and state government, California has recently been at the cutting edge of environmental controls. The entire domestic oil industry would be well advised to understand the regulatory role that has developed in California and incorporate that knowledge into the EOR planning process.

ENHANCED OIL RECOVERY TECHNOLOGIES

A technical discussion of the various facets of enhanced oil recovery technologies is reserved to other sources. This paper will concentrate on the impact that existing and developing laws and regulations will have on EOR activities. For organization purposes, three groups of technologies can be identified:ThermalMiscibleChemical

By examining the known and potential permitting problems that the use of thermal technologies may encounter, it is possible to address most of the problems that can be expected by the other technologies. The use of chemical EOR technologies will face a unique set of obstacles which will be examined separately.

THE LAWS AND REGULATIONS

Since the "great environmental awakening" of the late Sixties, Congress has enacted several major pieces of legislation to protect the nation's environment. These laws in turn spawned many state, regional, and local regulatory and planning activities. The scope and impact that these regulations will have on the economy and on specific industries is beginning to be understood.

The following is a partial list of the major pieces of federal legislation and some of the important ongoing programs that will, and are, directly affecting EOR activities:The Clean Air Act (CAA) of 1970PL 91–604, and the Clean Air Act Amendments (CAAA) of 1977, PL 95–95 and PL 95–190.Revisions of the State Implementation Plans (SIP).Air Quality Maintenance Planning (AQMP)Federal and state preconstruction review, e.g., New Source Review(NSR) and Prevention of Significant Deterioration Review (PSD).