This reference is for an abstract only. A full paper was not submitted for this conference.
The hammerless union is the next generation of union type products targeted at eliminating injuries associated with hammer union make-up. A guided hammer is connected to the union, and a few efficient 'sweet spot' strokes are all that is needed for proper make-up or rig down. This new union and tool are the collaborative user-manufacturer result of dozens of prototype trials in controlled shop environments and several field tests over a 2 year period. A study and final report from a licensed orthopedic physician confirmed that "tennis elbow" was not a significant risk with proper use of the tool.
Anticipated applications are well service temporary flowlines, with particular applications in fracturing, stimulation, cementing and process and pipelines operations. However, any area in which space is constrained or in which swinging a hammer is dangerous is a probable fit. The product is designed to be retro-fitted to existing Flowline products, greatly reducing the financial impact of switching costs.
This product was inspired by safety and the need to eliminate hammer related injuries. The product eliminates shrapnel, accidental hammer impacts, and repetitive use injuries. It also eliminates the need to grind lugs and increases the life of the unions, thus again reducing risk and costs associated with maintenance activities.
A patent application has been submitted for the hammerless union, tool, and the combination. The hammer union has been in use in the oil and gas industry for over 70 years. The hammerless union may be the first effort to successfully and practically replace the hammer in a significant part of make up operations. It also provides this safety incentive with little or no adverse effect to work productivity.
This paper will cover the development, testing and field trials emphasizing improved safety and user satisfaction.
Fischer, Daniel D. (Texas A and M U.) | Bilhartz, Dale (Texas A and M U.) | Holt, Charles (Texas A and M U.) | Johnson, Michelle (Texas A and M U.) | Breeze, B.J. (Texas A and M U.) | Aud, William W. (Texas A and M U.) | Crawford, Paul B. (Texas A and M U.)
Fischer, Daniel D.; Texas A and M U. Bilhartz, Dale; Texas A and M U. Holt, Charles; SPE, Texas A and M U. Johnson, Michelle; SPE, Texas A and M U. Breeze, B.J.; SPE, Texas A and M U. Aud, William W.; SPE, Texas A and M U. Crawford, Paul B.; SPE, Texas A and M U. Texas Petroleum Research Committee
Laboratory studies have been conducted to determine oil recovery of the North Cowden-Grayburg and Goldsmith 5,600-ft [1700-m] Clearfork crudes of west Texas when pushed by CO2 at various pressures. Studies were made at reservoir temperatures of 100 and 111 degrees F [38 and 44 degrees C] for the North Cowden and Goldsmith 5,600-ft [1700-m] crudes, respectively. At these temperatures, it was found that the oil recovery ranged from 57 to 99% as the CO2 pressure increased from 700 psi to 1,800 psi [4.8 to 12.4 MPa]. Normally the North Cowden crude gave a higher oil recovery throughout the pressure range. In recognition that CO2, may be in short supply, studies were made of the possibility of using a slug of CO2 pushed by nitrogen. For the slug tests the CO2 slugs ranged from 2.5% to 25% HCPV. All CO2 slugs were pushed by nitrogen. The oil recovery ranged from approximately 60 to 99% over this slug size. The data were obtained in slim-tube equipment ranging from 40 to 100 ft [12 to 30 m] in length.
The miscible bank formed between the CO2 and the body of the crude oil was observed to be a clear strawcolored liquid. The analyses of the clear liquid and crude oil conclusively demonstrate (1) that the crude oil undergoes a continuous fractionation process when miscibly displaced by CO2, (2) the need for tong flow tests, and (3) the inability to interpret most PVT cell data in terms of miscibility.
Most U.S. reservoirs have been substantially depleted by primary production and many of these reservoirs are now in the terminal stages of waterflooding. If abandoned, these oil reservoirs may still leave more oil underground than they have produced. Tertiary oil recovery methods are being developed to recover a large fraction of the original oil in place. One of the enhanced recovery methods receiving consideration is a process whereby a slug of CO2 is injected to achieve miscibility with the crude oil and the CO2 slug is displaced with nitrogen. This method reduces the amount of CO2 required, stretches the CO2 supply, and usually reduces the cost. This would permit a wider application of the CO2 miscible recovery process and, we hope, recover additional oil from our reservoirs. Nitrogen may cost approximately one half as much per thousand cubic feet (Mcf) [28 m 3] as CO2. For many oil reservoirs, 1 Mcf 129 m3] of nitrogen may occupy about three times as much reservoir pore space as the same amount of CO2.
Most of the known CO2 reserves are located in Colorado, New Mexico, Utah. and Mississippi. Much of the CO2 target oil is in the Permian Basin of west Texas and New Mexico. A pipeline will be required to transport CO2 to the prospective oil reservoirs. Several companies are moving forward with line construction. The hypothesized CO2 flood potential for west Texas alone has been estimated at 3 to 4 billion bbl [0.48 x 10(9) to 0.76 x 10(9) m3] of oil. This will require a lot of CO2. For a very thorough review of CO2 flooding, see Ref. 1, which cites more than 60 references.
Whereas CO2 for miscible displacement is in short supply, nitrogen is plentiful. The nitrogen would be obtained from the air by a cryogenic process. In this process, air is compressed and subsequently cooled to approximately - 300 degrees F [-184 degrees C]. At this temperature the air liquefies and permits fractionation and purification. The pure nitrogen is taken from the top of the fractionating column and warmed to a gaseous state near atmospheric temperature. The warm gaseous nitrogen is compressed for injection into the oil reservoir.
Wiesepape, Floyd C. (Texas Petroleum Research Committee, Texas A and M University) | Kennedy, H.T. (Texas Petroleum Research Committee, Texas A and M University) | Crawford, Paul B. (Texas Petroleum Research Committee, Texas A and M University)
A Devonian crude oil of 40 deg., API gravity and free of hydrogen sulfide, nitrogen or carbon dioxide and forming no precipitates when mixed with gas at high pressures was used as the base crude. Hexane, n-pentane, n-butane, propane, ethane gas and a natural gas were added to form the desired mixture.
The mixture was prepared so that it contained 20.06 percent C7+ in the total system.
Vapor-liquid equilibrium ratios (K-values) were determined experimentally on this Devonian crude oil - natural gas system containing 20 percent of the C7+ or heavy fraction. The data were obtained at 150 deg. and 350 deg. and several pressures. Comparisons are made between the experimental and GSA equilibrium ratios.
Prediction of the compositions and relative quantities of vapor and liquid phases of complex hydrocarbon mixtures depends on the use of equilibrium vaporization ratios, or K-values which are defined as
yi Ki = .........................(1) xi
where: Ki = K-value of the ith component yi = mol fraction of the ith component in the vapor phase
xi = mol fraction of the ith component in the liquid phase
This paper was prepared for the 49th Annual Fall Meeting of the Society of Petroleum Engineers of AIME, to be held in Houston, Texas, Oct. 6-9, 1974. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgement of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor of the appropriate journal provided agreement to give proper credit is made. provided agreement to give proper credit is made. Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines.
The behavior of displacement mechanisms through pattern developed reservoirs has been studied extensively utilizing a great variety of methods. Basically, the methods of study have involved observation of physical laboratory models, analytical solutions, and numerical solutions. All three methods have their own unique disadvantages. Physical models are usually small, simple, and very time consuming to build and operate. Analytical solutions can only be treated as approximations when heterogeneities are introduced. Numerical solutions become quite costly when a great deal of detail is involved in the study because of the large number of cells required for proper simulation.
A streamline approach has been applied to analytical methods to provide a greater degree of accuracy in the study of displacement processes. This approach has been an improvement processes. This approach has been an improvement over past methods; however, it is still not conducive for studying heterogeneities in the reservoir, and no provision is made for either horizontal or vertical crossflow components during the displacement program.
This paper proposes the study and application whereby the streamlines closely approach the numerical grid of the digital computer. The five-spot pattern has been treated by aligning a numerical simulator into a bi-radial divergent-convergent grid arrangement. Such representations correspond closely to flow from input to output wells. This grid alignment has made critical observation possible in any region desired without excessive cells in unnecessary regions of the system in order to satisfy the boundary or symmetry requirement of the numeric model. The divergent-convergent radial grid arrangement allows solutions through the five-spot octant at considerably less expense than with the conventional rectangular grid arrangement. In addition, well pressures may be computed in keeping with the numerical solution, heterogeneous reservoirs can be simulated, and crossflow components are provided.
The success of a displacement process in a reservoir is primarily influenced by the volumetric sweep efficiency. Volumetric sweep efficiency is defined as the displaceable reservoir volume divided by the total reservoir volume. Sweep efficiencies are known to vary considerably as a function of the injection pattern and the mobility ratio between the pattern and the mobility ratio between the injected and displaced fluids.
Sweep behavior has been the subject of extensive research through analytical and laboratory studies.
This paper was prepared for the 48th Annual Fall Meeting of the Society of Petroleum Engineers of AIME, to be held in Las Vegas, Nev., Sept. 30-Oct. 3, 1973. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The 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 the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor of the appropriate journal provided agreement to give proper credit is made.
Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines.
The water flooding performance in homogeneous or isolated layered systems has been well documented in the technical literature; however, the literature does not indicate that work has been conducted on the flooding performance of a fractured matrix reservoir performance of a fractured matrix reservoir subject to a bottom-water drive. It is generally believed that flooding of a fractured matrix reservoir would not recover much of the oil because the water would move faster through the fracture ant there would be an early breakthrough of the water, yet this has not been demonstrated for a bottom-water drive.
A model to represent one element of a fractured matrix reservoir was constructed. The model was positioned vertically and water was injected at a constant rate in the bottom and oil was produced from the top of the model. The experiments were made with different initial water saturations using unconsolidated sands.
In this study it was observed that imbibition rather than the direct displacement of oil by water was the dominant mechanism in the recovery of oil from a fractured matrix.
The oil-water interface was observed to be four to fifteen inches higher in the matrix than in the fracture. For some systems the oil-water interface stabilized at about five inches higher in the matrix than the fracture.
Oil recovery from the fractured matrix ranged from 27 to as high as 77 percent of the initial oil-in-place. Low initial water saturations resulted in a greater percentage oil recovery.
It is concluded that thick, fractured matrix reservoirs may be engineered for successful flooding by bottom-water drives.
The fractured reservoir and the detrimental effect of fractures on secondary and tertiary recovery programs has been recognized for many years. It has been thought that water flooding of a fractured reservoir may not recover much of the oil because the water would move through the fracture and there would be an early breakthrough of the water. Much of the oil would be bypassed.
1973 Third Symposium on Numerical Simulation of Reservoir Performance, Houston, Texas January 11-12, 1973. Performance, Houston, Texas January 11-12, 1973
Computer modeling of petroleum reservoirs leads one to the problem of solving large numbers of simultaneous fluid flow equations. The purpose of this paper is to propose a new method for solving these equations and present comparisons between our method and the strongly implicit procedure (SIP) proposed by Stone and others. We have compared the new technique with SIP for a number of two-dimensional, steady state problems in both homogeneous and strongly heterogeneous reservoirs, with reservoir sizes ranging from 100 to 800 blocks. For some heterogeneous cases the ratios of transmission coefficients varied by a ratio of one million to one for testing. Compared to SIP, our method requires less computer storage space, compiles faster, executes up to 2.96 times faster, has no iteration parameter, is easier to program, requires about two-thirds an many cards, and gives excellent agreement in regard to material balance and final values of Pi,j. The method has been applied to problems with from 2 to 16 wells positioned in the reservoir corners, immediately adjacent, in line, and in random positions. Well magnitudes have been allowed to range up to a ratio positions. Well magnitudes have been allowed to range up to a ratio of 10,000 to 1.0 in the same problem. For every problem thus far attempted, the method has converged to the same answers as SIP in less computer time. Based upon our experience with this new method, we feel that the new method is substantially superior to SIP.
American Institute of Mining, Metallurgical and Petroleum Engineers, Inc.
A study has been made and a series of charts are provided so that one may estimate the swept areas after breakthrough in flooding or cycling heterogeneous reservoirs. It is well known that reservoirs are not uniform and homogeneous, nor do they exist in uniform layers without crossflow, yet, the working charts and figures available to the engineer assume uniformity of the rock from an input well to an output well.
A series of charts has been developed various flooding patterns to show the swept areas after breakthrough for the case in which the rock is heterogeneous in nature, and the heterogeneity is distributed at random within the rock matrix. To use the charts one makes a plot of the permeability distribution data for the field and then refers to a figure in the paper to find a permeability distribution data paper to find a permeability distribution data nearest that of the real reservoir from this figure one then refers to the proper pattern such as five-spot or direct line-drive to find the expected areal sweep at breakthrough and performance afterward to depletion. performance afterward to depletion
Commencing about thirty years ago a number of methods have been presented in the literature for estimating the performance, area swept at breakthrough and after breakthrough for waterflooding and pressure maintenance programs.
In the early analytical work Muskat reported on the calculated sweep efficiency. His work showed the sweep efficiency for the five-spot and direct line-drive, square pattern, to be of the order of 72 percent and 56 percent, respectively. Muskat's calculated percent, respectively. Muskat's calculated results were based on a uniform homogeneous rock, fluid mobility ratio of one, gravity effects were neglected and capillary effects were neglected. His work has served as the basis for many computations.
An unusually fine paper on engineering waterfloods was presented by Herman Dykstra and R. L. Parsons at the May 1948 API Meeting in Los Angeles. In the DykstraParsons method it was suggested that a straight line may result when the cumulative percentages of samples were plotted against the logarithm of the permeability.
When oil is produced above the bubble point from a reservoir having a large aquifer, there usually exist three zones affecting the transient pressure distribution. These zones are the oil zone, aquifer and the transition zone between the oil and aquifer. This paper shows the development of the equations giving the transient paper shows the development of the equations giving the transient pressure distribution for the case of constant pressure production pressure distribution for the case of constant pressure production in a linear system having different mobilities in each of the three zones and a third mobility in the oil-water transition region. The study of Van Everdingen and Hurst showing the derivations of equations leading to the transient pressure distribution has been widely used both for oil and gas reservoirs having expanding aquifers as their principal source of energy. Their work assumes that the properties of the fluids in both the hydrocarbon zone and the water zone are the same.
American Institute of Mining, Metallurgical and Petroleum Engineers Inc.
This paper was prepared for the 45th Annual Fall Meeting of the Society of Petroleum Engineers of AIME, to be held in Houston, Tex., Oct 4-7, 1970. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The 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 the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon requested to the Editor of the appropriate journal, provided agreement to give proper credit is made.
Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussions may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines.
Cybernetics has been under development for almost 50 years but only during the past 20 years has it evolved into a scientific approach to aid in the analysis of systems existing in the so-called "black box". Petroleum reservoirs are always in the black Petroleum reservoirs are always in the black box category in that the precise reservoir shape, rock and fluid physical properties are never really known even though the reservoir is produced to abandonment.
Cybernetics has been applied to a water-drive reservoir near abandonment conditions. The cybernetic method was found to forecast the performance of this reservoir quite accurately when only a small fraction of the fluid had been produced. Cybernetics does not require detailed information such as rock porosity, permeability, areas, thickness, fluid porosity, permeability, areas, thickness, fluid compressibilities, etc., desired for the conventional influx calculation.
In the past 30 years the science of petroleum reservoir engineering has emerged petroleum reservoir engineering has emerged as a well-defined and highly technical branch of petroleum engineering. Extensive investments in facilities and personnel for the recovery of oil and gas are now made routinely on the basis of reservoir performances predicted by reservoir engineering studies. Reservoir engineers and research investigators are pioneering and developing new techniques for pioneering and developing new techniques for improving recovery of oil and gas. Greater accuracy in reservoir performance calculations will bring the industry closer to the ultimate goal of obtaining the maximum efficiency in the exploitation of petroleum reservoirs.
The van Everdingen and Hurst technique of estimating performance of water-drive reservoirs based on compressible flow theory has been presented in the literature as the most generally successful. However, their method applies to radial reservoirs surrounded by infinite or radial aquifers of constant rock and fluid properties. k complete knowledge of the properties of the reservoir and aquifer is desired for applying the technique. The method also requires knowledge of the pressures at the boundary of the reservoir and quifer. Average reservoir pressures are usually used when the boundary pressures are not known.
In practice, besides incomplete knowledge of reservoir properties, there is uncertainty in the aquifer properties, which are generally estimated from wells drilled in the reservoir. On the other hand, there exists uncertainty in the reservoir pressure history. Thus, all of these factors combined contribute to make the van Everdingen and Hurst technique of limited value in many practical cases.