The rapid expansion of the petroleum industry has caused a shortage of experienced field personnel. Even though there are volumes upon volumes written regarding specific stimulation techniques and processes, one finds that many of the routine aspects of performing these treatments are overlooked. We will look specifically at a study of optimized perforation costs in relation to hydraulic horsepower requirements, optimization of stimulation fluids - first in terms of unit cost, and then take a particular fluid and look at treatment cost compared to productivity increase.

Hot oil treatment of flowline and downhole paraffin problems is still common in the oilfields of North America. The use of chemical programs has been growing but often the industry is unsure which type of treatment should be done and if these programs are more cost effective than hot oiling. This paper will attempt to show, based on the paraffin problems being experienced, which type of chemical treatment would be most cost effective. Case histories of economic treating programs will be presented.

Matrix acidizing is often undertaken to improve the permeability of reservoir rock. When excessive quantities of ferric (Fe+++) ions are taken into solution by matrix acidizing, iron deposition and permeability reductions can occur after acidization. Sources of iron include (1) iron oxides from tubular goods, (2) pipe scale and (3) iron in mineralogical form such as siderite, pyrrhotite, magnetite, hematite and pyrite. Preventing iron deposition in matrix acidizing is essential to a successful acid treatment. This paper details a relatively new technique for controlling the precipitation of ferric compounds in matrix acidizing by incorporating a reducing agent/chelator blend. This new method is compared to three older techniques commonly used in iron control: buffering the pH, chelating, and a combination of buffering and chelating. Using standard wet chemical methods, the sequestering capabilities of the various iron control methods are evaluated at various values of pH and temperature. The effect of calcium ions on iron-sequestering capacity is also demonstrated in the paper.

This paper presents a discussion of fracture height measured with gamma ray and temperature surveys and fracture height predicted with a real-time model during the pumping of a fracture treatment. The San Andres formation was fracture stimulated ii; six West Texas wells. Each treatment was pumped down the annulus with open-ended tubing in the hole. The open ended tubing pressure was monitored to obtain direct measurement of bottom-hole treating pressure. Throughout each treatment a real-time quasi 3D fracture model was run to predict fracture geometry. After each treatment, gamma ray surveys were run to determine fracture height. A temperature survey was also run in three of the wells. Excellent agreement was obtained between the post stimulation survey fracture height and the quasi 3D model predicted fracture height.

Many times a certain prime mover is selected because that particular make and size is known to the purchaser. Little or no consideration is given to the various types of engines available, one of which may be best for the particular installation. To make an intelligent comparison of slow and high speed engines and be able to make a proper selection of a prime mover for a particular installation it is necessary to understand the definition, the principle of operation, the mechanical construction, and the advantages and disadvantages of each type of engine.

Rod pumping units historically used a crank driven walking beam to provide a reciprocating motion for oil and gas production. Several geometries have evolved over the years to produce desirable polished rod motion profiles and gearbox torque loads. These mechanical systems are limited in their ability to manipulate the motion profile and the profile is forever fixed by the selected geometry. Hydraulic cylinder linear actuators became available a number of years ago for reciprocating rod pumping of oil and gas wells. Electrically driven rack and pinion linear actuators have also been recently developed for rod pumping applications. These hydraulic and electric linear pumping units share some common advantages over mechanical pumping units. Linear pumping units are generally less massive than comparable walking beam units and can be mounted directly to the well head. The cost savings on site preparation, transportation logistics, and equipment installation can be substantial. Linear actuators also have an important advantage in their ability to provide programmable control of polished rod motion profile and closed loop control of polished rod load. The relatively low mass of linear actuator mechanisms allows nearly instantaneous adjustment of polished rod velocity and load. Linear pumping units provide independent control of up stroke and down stroke peak velocities as well as the shape of the velocity profile. Controlling the velocity profile allows increased pump cycle rate and associated production without exceeding rod fall velocity limits. Velocity profile control can also be used to reduce gas interference and fluid pound. Rod stroke position can be controlled to provide period pump tapping to overcome down-hole pump problems. Polished rod load control can be used limit minimum rod load, eliminate bridle separation, and damp rod load oscillation.

In lieu of pending EPA and NRC regulations covering the monitoring of ground water supplies of drinking water as it relates to the public health, both private and municipal water districts, and utilities will be required to monitor for naturally occurring radioactive materials, NORM, and their constituents, ie... Radon, Radium, and Thorium. This monitoring will require the utility districts to utilize and employ "BAT", best available technology. A more advanced set of CAE, computer aided engineering, tools are beginning to appear that combine data, graphics, and analysis capabilities within a spatial model. CAE tools are considered in this paper to fit into the BAT category. CAE can assist independent water districts as well as broad based watershed and aquifers utilized by municipal water districts in data management, engineering analysis and complex site visualization. Water companies can project regions that could create an environmental impact on public health. Data involved, ie... mechanics of ore zone hydrology in aquifers, in site assessment and analysis can now be integrated into a single model called a virtual site. The virtual site concept of data management uses an electronic version of a geotechnical engineer's conceptual site model. Please refer to Appendix A for a more detailed description. The petroleum industry is also being impacted by a multitude of environmental issues, both past and pending legislation. Many petroleum companies are initiating a proactive environmental policy. CAE functionality can assist them by providing a vehicle for complex site data management, engineering analysis and site visualization. Concurrently, NORM is under proposed regulations (Revision 3) under the Texas Department of Health Radiation Control. Using the virtual site, engineers can directly query, edit, or manipulate data while the consequences of changes made cascade through the model. To explore the many ramifications of NORM and other potential environmental hazards, 3D graphical presentations of site specific scientific visualizations can be calculated and displayed on the fly.

The variation of centrifugal pump performance curves with liquid viscosity is a well-known fact and is usually properly accounted for when selecting such pumps for oilfield service like artificial lifting by ESP units, pipeline transport, etc. Thus, several theoretical and empirical methods are available for correcting performance curves (conventionally measured with water) to other liquids. Most of them utilize specially developed charts and tedious hand calculations and are viable for simple design calculations but find very limited use when a great number of cases is present or when computerized calculations are desired. The aim of the present paper is the development of specific formulas instead of charts to be used for correcting the performance curves of centrifugal pumps for higher viscosities. The formulas are based on the widely used and generally accepted procedure of the Hydraulic Institute whose previously published charts, after digitalization, were fitted with analytical functions of the relevant parameters. The model introduced in the paper easily lends itself to computer applications and may be used as a subroutine in many kinds of program packages that involve selection or evaluation of centrifugal pumps. The use of the model is illustrated by a detailed example problem. At the end of the paper, two additional examples are shown to prove the accuracy of the proposed model. Here, calculated performance curves are compared to actually measured ones for two pumps in pipeline service. The two examples prove that the proposed analytical model gives very good accuracies.

Before we start to discuss "Optimum Pumping Conditions" let us first see what Webster's Dictionary gives as the real meaning of "optimum": "The best or most favorable degree. Best, most favorable or most conducive to a given end, especially under fixed conditions." The first and most important key to optimum pumping is the establishment of fixed conditions. As we all well know, the basic purpose of any pumping installation is to pump fluid from the well to the surface. In order to establish a set of fixed conditions around which we can establish optimum pumping, we must consider all of these factors which are most important and then we must decide to what degree they really are fixed or stable.

A comparison was made between four commercially available sucker rod string design programs: Rod Star, S-Rod, Q-Rod, LoadCal B and a proprietary, modified API RP11L based program. These programs used the same input requirements, where applicable, and their outputs compared dynamometers cards from five different producing wells. The results show differences in the anticipated major design loads along with differences in the output information. Recommendations are made on potential changes to these programs and comments are made on things to consider when these programs are used.

A geographical and lithological diagram pertaining to oil well cementing is presented for the Delaware Basin of West Texas and New Mexico. The composite cementing programs were selected from jobs performed in the area. Jobs selected were used as examples of design considerations for the problems which can be expected in the area. The materials and equipment are discussed in relationship to formation conditions which determine their selection. Cementing techniques of the area are presented in detail. One method considered unique to the area is presented. Particular attention is given to the difficult combination of lost circulation formations having low break-down pressure associated with relatively high pressure formations. The considerations of high temperature cementing are discussed in relationship to the deeper formations. This presentation considers the basic chemical and physical properties of cementing materials and their use to satisfy the design considerations necessary to successful cementing operations in the Delaware Basin.

Fluid pound has long been a problem with maintaining good run life of the pumping system. The result of fluid pounding is costly and deprives the industry of dollars that can be used to invest in improvements instead of repairs. With the bottom line decreasing, how can each operator remain in business and stay profitable? The cost of making that extra barrel of oil may be greater than the revenue received.

A discussion of the Cummin CD&W San Andres waterflood project in Ector County, Texas is presented. This waterflood, operated by Cities Service Oil Company, began in 1961 with a pilot consisting of four water injection wells and one oil well. The project has been expanded to twenty-eight injection wells and twenty-five oil wells based on the results of the pilot project. Secondary oil recovery to date exceeds 800,000 barrels. The success of the project has been attributed to close spacing of water injection wells and relatively low water injection rates.

When an operator is faced with the prospect of fracture treating large pay intervals, several options exist. The most popular technique appears to be single stage limited entry, followed by multiple stages with bridge plugs or baffle rings. With the growing acceptance of 3-D fracture simulators the technique of cluster perforating has provided a third option. The 3-D models often suggest that large intervals can be effectively connected to the wellbore using a single propped fracture initiated from a relatively small perforated interval. This technique is often unpopular with operators who feel that each foot of net pay must be connected to the wellbore with a perforation. Perforating large intervals may lead to the creation of multiple fractures, though, especially when the wellbore or fracture is not vertical. . This can be counterproductive to maximizing fracture lengths, particularly when the design assumed- a single fracture. Field examples are provided to support the theory of multiple fractures and small interval perforating. A model is then presented to aid in the staging and perforation design process.

This paper will review how the current electronic tubing inspection equipment and interpretative techniques are being applied on field tubing inspection and electronic scanning jobs.

The primary function of a well service rig during the well maintenance process is to retrieve and run drill pipe, tubing, and/or sucker rods. Producers recognize that the proper assembly of these well components is critical to maximizing the time between maintenance jobs, and to maximizing profitability. Producer and contractor management alike, have the expectation that rig personnel can meet optimum torque requirements specified by manufacturers of these tubular goods. However, the equipment available to crews to accomplish their work has not significantly changed in decades. Generally, there is a minimal understanding at any level of the many affects that various rig components have on the assembly process. This paper will describe and illustrate some of the factors affecting the critical process of torque application to both shouldered and non-shouldered connections.

Lockheed Petroleum Services Ltd. offers an oil and gas production system that allows operators to locate much of the producing equipment on the ocean floor, out of sight and far removed from shipping and weather hazards. Oil and gas wells are drilled from a drillship or semisubmersible drilling rig, and submarine flow lines carry produced fluids to a nearby platform. With this system. a large oil or gas field can be developed without using multiple platforms, as one will serve " an entire field when subsea well completions are used.

A faster downstroke in a beam and sucker rod pumping system, traditionally considered unfavorable to the best production practices, may have some surprising, beneficial side effects not readily apparent to the casual observer. This particular kinematic characteristic may increase productivity in several ways; reduce peak rod and structural load and maximum rod stress; deliver more safe work to the bottomhole pump; and in some cases even decrease rod load range and soften the impact resulting from fluid and gas pound. The following discussion illuminates some aspects of this often misunderstood characteristic of reverse geometry units like the air balance and Mark II.

With the increased use of polysaccharides in fracturing treatments, subsequent problems have been encountered with inadequate polymer hydration, weak or over crosslinked fluid, formation of fish eyes, low viscosity and uncontrolled breakout. Problems have also occurred due to inadvertent contamination from water supplies and fracturing tanks. In field studies of the Lost Hills and South Belridge areas in Kern County, Calif., field conditions and operational procedures were found to constitute critical factors in successful dispersion and in ideal cross-linking of polysaccharides. A comparison of field fluids with laboratory fluids was conducted with special emphasis on the quality of field water and on the effects of pH and temperature on the viscosity and sand fall rate. Laboratory tests indicate that fluid mixed in the field can exhibit a more effective cross-linking structure, a more stable viscosity strength and a lower sand fall rate if more control is exercised in the determination of pH range, in the selection of buffers and in the choice of treating water. Attention to these factors, as pointed out in this paper, can reduce lost time, save expense and increase well performance.

A safe and effective biological paraffin control technology, based on the use of a mixed culture of naturally occurring bacteria, has been developed by Kiseki Inc. A research program was undertaken to determine the main mode of action of the microbial paraffin control technology. From the initial phase of this study, the results from field studies on 26 oil wells in Alberta are discussed in relation to the use of bacterial counts in the produced fluid as an indication of effective paraffin control downhole.

A presentation of a three year field study covering 225 pumping wells from depths of 400 to 8000 feet utilizing electrical and internal combustion prime movers. Operational and maintenance costs, motor controls, accessories, record and inspection programs for both methods are discussed.

The primary purpose of this paper is to present a field evaluation of paraffin problems and to show how they can be alleviated by using certain plastic flow lines and plastic coated tubing. In order to more fully examine the advantages and disadvantages of the various methods available, a paraffin cost study of Field A and Field B is presented.

Diverting methods have been developed and used extensively to distribute treating fluids in a zone or to divert them from one zone to another. Diverting may be accomplished mechanically or chemically. Mechanical diverting with perforation-sealing balls is a common procedure, but conditions may exist which make it ineffective. The height of the zone, number of perforations, limited pump rate, and capacity of the formation to take fluid are factors which may lower fluid velocity so that it is not adequate to seat the balls on the perforations. Communication between perforations or behind the casing, or perforations that are not round also may limit the effectiveness of ball sealers. for an impermeable gel diverting system was recognized. A gel diverting system, in order to be used as a diverter in acidizing treatments, has to meet the following criteria: the gel has to have a low viscosity during placement, hydrate to form a solid impermeable gel in the formation, revert with time to a liquid for removal, and leave a minimum of permeability damage. Packers also have provided effective mechanical diverting. However, they are more difficult to use because their effectiveness is dependent on accurately locating the zone to be treated and accurately setting the packer to isolate this zone. Numerous soluble particulated solids, which are often referred to as temporary bridging agents, have been developed for fluid diversion. These are solid chemicals that have varying physical and chemical properties. An agent can usually be selected that is satisfactory for a specific treating operation. These diverting agents usually are transported in a viscous carrier fluid and are pumped between stages of treating fluid. The effectiveness is dependent on the strength and permeability of the bridge formed. Some solid diverters have a wide particle size distribution and form low permeability bridges, but their permeability is not, low enough to effectively divert treating fluids to zones having a permeability less than about 2 md, and the need Various chemical types of gelling agents were evaluated in order to obtain a feasible gel diverting system. On the basis of the gelation time and stability tests, only two gelling agents appeared to meet the necessary criteria. One of these gelling agents was a high-residue natural gum and the other was a low-residue modified natural gum. A gel diverting system using the low-residue gum was finally selected since the diverting-efficiency and permeability-recovery tests showed that using the high-residue gum resulted in permeability damage. So, only the data using the low-residue gel system are presented in this paper, except in the diverting efficiency and permeability-recovery tests, in which case the data from tests using both the high and low residue gums are presented. The procedure used on a field job is presented, and the results are described.

The oil and gas regulatory data mapping portal was introduced to New Mexico in 2009. The purpose of the mapping portal was to help oil and gas operators, natural resource environmental managers, and other related sector professionals evaluate natural resources and man-made features within a subject area. While initially designed for the New Mexico Pit Rule, the data provided by the portal has proven to be useful for other applications and beyond the borders of New Mexico. The mapping portal has been expanded to include data for surrounding states. Mapped natural resources include, but not limited to: depth to water and ground water elevation from USGS gauging stations; topography; aerial photos, digital elevation models; surface geology; karsts; and surface water. In addition, the mapping portal includes spatial search capabilities that allow querying data to determine proximity of natural resources to a subject site. The mapping portal is available at http://saturn.nmt.edu.

Success and progress in our industry depend upon a coordinated system of integrated activities seeking, but not always maintaining, a balance between production and consumption. We must continue to advance in the technology of finding, producing, transporting and refining petroleum, and, as well, in the transformation of the raw materials into useful products through petrochemical processes. We recognize, therefore, that a good job much be done up and down the line.