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Exploration for natural gas in the Sheep Mountain area, located approximately 28 miles northwest of Walsenburg, Colorado, was begun in early 1972. The first two wells completed produced CO2 instead of natural gas. ARC0 Oil and Gas Company purchased the leases from the original lease holders in 1974 and continued development of the field. The boundaries of the Sheep Mountain Unit were finalized in 1981, and the Unit now consists of approximately 9,000 acres.

A gas separator has been developed and successfully field tested in several beam pumped wells which were subject to severe gas interference. The new design is based on several innovations: l Decentralization of the gas separator in the casing, insures that a minimum amount of gas enters the separator. l The presence of two or more ports located on the narrow side of the annulus where the gas separator touches the casing wall. l Sizing the OD of the outer tube of the separator so that it is equal to or greater than the OD of the tubing collars.

Proper implementation of a successful polymer flood is facilitated if certain engineering requirements are considered. A recommended sequence of events is outlined to describe engineering requirements for a polymer flood. An overview of the feasibility, design, and start-up phases and a more detailed discussion of some aspects follow.

This paper is presented to assist those involved in designing, installing and operating source water pipe line systems to serve waterflood operations. The design and installation of the source water system to supply Capitan reef water, produced in Winkler County, Texas to various waterflood operations in the Ector County area will be discussed in detail to indicate the various problems which are encountered in the design and operation of this type of facility.

A carbon dioxide (CO2) supply well was drilled and completed by Conoco Inc. in the Elsinore Field, Pecos County, Texas in September, 1983. The well was drilled toprovide CO2 for the Ford Geraldine (Delaware Sand) Unit, Reeves and Culberson Counties, Texas. The well tested flowing 11.5 MMCFPD of saturated CO2 at a pressure above the critical. The corrosive nature of the saturated CO2 at a pressure above the critical
necessitated a careful study of pipeline 4 g and dehydration options.

Accurate hydrocarbon measurement requires equipment and methodologies that enhance out ability to minimize uncertainties. The purpose of this paper is to discuss the advantages of LACT measurement versus tank gauging and to address the carious technologies utilized in determining the quantity and quality of liquid hydrocarbons in custody transfer service. In addition, this presentation will address proper design and operation of such LACT components as recommended by API.

The gas lift system of artificial lift is basically a four component system. The components are designed to fit individual well requirements, but more important is that the design of each component is compatible with the remaining components of the total system. Too often this is overlooked. With a good understanding of the four components, their dependence on each other, their variations as dictated by the well data, and their effect on the total system; the engineer is equipped to design a very efficient lift system.

The sucker rod pump is the oldest and still the most widely used means of artificially lifting oil from the well bore. With the demand for higher volumes, from greater depths, with high gas-oil ratios and the use of propping agents in fracturing, the service and performance of the down well pump is greatly impaired. Careful selection of pumps and operating techniques will increase the performance and insure an economical operation.

Ten years age the name "Thermal Recovery" was usually applied to the forward combustion oil recovery process. Today, so many variations of oil reservoir heating methods have been proposed and tested that "Thermal Recovery" now has a far more general meaning. Any oil recovery process which depends upon application of heat to a reservoir is a thermal recovery process.

The purpose of this paper is to outline and illustrate the calculations required to design a closed rotative gas lift system. Design considerations that are required for continual operation of a closed rotative system without make-up gas after initial charging are discussed. Detailed calculations for a single intermittent well system are offered. These calculations are presented in a step-by-step manner. The effect of expanding the system to include other wells is illustrated.

Ultra-high-slip motors with speed variation capabilities in the range of 45% have been used on beam pumping installations for more than six years. As various producing companies started trying these motors, many improvements in system operation were noted, including: 1. Reduction in peak polished rod load 2. Increase in minimum polished rod load 3. Improved rod life 4. Reduction in peak torque by the API Torque Factor Method 5. A greatly altered dynamometer card shape which showed a tendency to approach the rectangular or parallelogram configuration 6.

This paper will stress the importance of understanding the various types of corrosion which occur in a well; to do this it is necessary to understand why and under what conditions they occur. Then, the proper cementing composition and procedure can be selected to help prevent the problem from reoccurring.

A 4-ft by 12-ft transparent, vertical fracture model is used to study the prop-carrying abilities of both non- Newtonian and Newtonian fluids. The design parameters and difficulties encountered in building and operating the model are discussed. Solutions to problems such as uniform distribution of prop in the sample area, uniform flow across the sample area, and reduction of end effects are described. A novel technique is used to record and reduce the prop trajectories. Observations of suspended prop flow in vertical fractures are presented.

The reservoir engineering aspects of the design of a major West Texas co2 flood are presented. The design included (1) a detailed fieldwide geologic study to characterize the principal Yates reservoirs, (2) a CO2 injectivity test to identify any reduction in injectivity either during or following CO2 injection, (3) laboratory work including oil-CO2 phase behavior, slim tube tests with pure and contaminated CO2 corefloods to determine recovery of waterf lood residual oil by CO2 flooding, (4) reservoir simulation to predict flood performance.

A general method for designing submersible electric pumping systems is presented. The technique is based on a mathematical model of the pumping system which includes mechanical, fluid dynamical and electrical simulations. Basic parameters which affect the design of a submersible electric system are discussed. To illustrate the technique, applications are made to high water cut (non-gassy) wells, high GOR (gassy) wells, variable frequency drives and tapered pumps.

This discussion is limited to salt water disposal systems where the salt water is to be injected into a subsurface formation. The subsurface formation may be the same formation from which the water was produced or some other one. The injection of salt water may be solely a means of disposal or it may be injected as a part of a waterflood or pressure maintenance project. Systems for subsurface disposal of salt water will usually include the injection well, injection plant, treating plant and the salt water gathering system.

In order to meet the codes and standards regarding equipment to be used in hydrogen sulfide service, there are several basic design criteria which must be met. The regulations specifically referred to in this technical paper are the Statewide Rule 36(l) as established by the Texas Railroad Commission, and Standard MR-Ol-75(2), as established by the National Association of Corrosion Engineers (NACE).

Effective mud removal of drilling fluids from the wellbore is still a major problem in cementing. Although good pipe centralization has been known for years to be one of the keys to the success of the operation, most current design procedures do not allow pipe standoff to be taken into account. When attempting to displace a mud in an eccentric annulus with a fluid thought to be in turbulent flow, it is shown that the displacing fluid can channel through the mud. An explanation for this phenomenon is given and a solution is proposed.

Effective mud removal of drilling fluids from the wellbore is still a major problem in cementing. Although good pipe centralization has been known for years to be one of the keys to the success of the operation, most current design procedures do not allow pipe standoff to be taken into account. When attempting to displace a mud in an eccentric annulus with a fluid thought to be in turbulent flow, it is shown that the displacing fluid can channel through the mud. An explanation for this phenomenon is given and a solution is proposed.

The sucker rod string for rod pumped wells can be adequately designed from hand calculations using API RP 11L1 or computer programs. While these methods will provide very good approximations of the loads and related stresses on the sucker rods and pumping system, they do not consider the loads the downhole equipment will be subjected to if a downhole pump is stuck and the rods are used to try to unseat the pump.
This paper will discuss the basic loads on the sucker rods when they are subjected to the fluid loads and forces when trying to unseat the pump.

Numerous technical papers have been written on the subject of analyzing the pressure-decline data from a mini-frac. Most of the publications written, however, have dealt mainly with the theoretical modeling of the pressure decline and not the practical application of performing a mini-frac in the field. The intent of this paper is not necessarily to discuss the theoretical analysis and design applications of modeling mini-fracs, but to discuss the practical steps involved to properly design, execute and evaluate a mini-frac. The basic concept of the mini-frac is presented.

ARCO Oil and Gas Company started work on a tertiary CO2 Pilot in the Garber Field during early 1980. The purpose of the pilot was to investigate the CO2 flooding of relatively shallow sands which were previously waterflooded to depletion. The pilot is in the Crews sand, a shallow Pennsylvanian sand, located at an average depth of 1950 ft. The main pilot is a 10.4 acres, normal 5-spot, which is enclosed by backup water injectors and outside producers. It was initially waterflooded to raise the reservoir pressure and to establish a base production curve.

The important factors concerning gear reducer design are discussed. Various phases of operational and maintenance control and the effect of improper application of these principles are reviewed.

The controlling features in a designed beam pumping system are: the desired production volume, optimum subsurface pump, gas anchor, sucker rod string including a sinker bar section, polished rod, tubing, V-belt drive, prime mover and the pumping unit. The design of each of these components is discussed in a step-by-step fashion. The governing assumptions are given, and all pertinent calculations are presented.

The purpose of this paper is to outline the procedure for designing an efficient closed rotative gas lift system. The system discussed includes both continuous-flow and intermittent gas lift wells. The importance of considering future as well as present gas requirements is noted. Adequate capacities of the high-pressure injection and the low-pressure gas systems are emphasized. Intermitting gas lift characteristics are reviewed to emphasize further the necessity for adequate volumes in both the low-and the high-pressure systems.