OCTG Connection Testing Aiding in the Integrity of Multi-Fractured Horizontal Wells

Abstract With the increase in shale oil and gas activity and complexity, companies deploy new solutions to safely and efficiently drill, complete, and produce wells in unconventional plays. These include Oil Country Tubular Goods (OCTG) connections, which must withstand installation, stimulation, and production loads specific to this application. Industry available standards provide manufacturers and operators a framework for quality founded on best practices and testing. In some instances, existing testing protocols may not be adequate (e.g. insufficient or overconservative) to assess connections’ performance for this application. For this reason, the American Petroleum Institute established an expert working group to develop Technical Report 5SF (TR 5SF) intended to evaluate casing connections performance in multi-fractured horizontal wells. The objective of this paper is to present a set of verified testing protocols applicable to casing connections used in the most common shale plays, complementing the existing body of knowledge. We discuss testing elements and parameters tailored to the conditions of various shale plays. Based on the operations planned for the life of a well, the testing procedure is adjusted to resemble the expected conditions and loads in the correct order. This includes make-up, high-cycle fatigue associated with the casing string installation, thread compound degradation under temperature and time, and mechanical load cycles generated by stimulation. Specimen sealability is confirmed under production loads, after which failure testing is performed. Some of the inputs to build the testing protocol are: maximum internal pressure, axial load, dogleg severity, number of cycles, temperature, and fluid type. Since connections play a crucial role in the integrity of a well, a testing procedure to ensure their performance is shown. Testing protocols for Multi-fractured Horizontal Wells (MFHW) applied to two connection types are presented, highlighting how tailored testing protocols and robust engineering improve product reliability and well integrity assurance. We compile a set of testing inputs for the most relevant shale plays worldwide, together with the testing elements, sequence, and acceptance criteria. This should help end users validate and benchmark products’ performance while improving industry knowledge of connections capabilities.

Download Full-text

A New Approach To Estimating Ultimate Recovery for Multistage Hydraulically Fractured Horizontal Wells by Utilizing Completion Parameters Using Machine Learning

SPE Production & Operations ◽

10.2118/204470-pa ◽

2021 ◽

pp. 1-16

Author(s):

Sulaiman A. Alarifi ◽

Jennifer Miskimins

Keyword(s):

Oil And Gas ◽

Horizontal Wells ◽

Oil And Gas Industry ◽

Gas Industry ◽

New Approach ◽

History Data ◽

Well Completion ◽

Production History ◽

Early Production ◽

Fractured Horizontal Wells

Summary Reserves estimation is an essential part of developing any reservoir. Predicting the long-term production performance and estimated ultimate recovery (EUR) in unconventional wells has always been a challenge. Developing a reliable and accurate production forecast in the oil and gas industry is mandatory because it plays a crucial part in decision-making. Several methods are used to estimate EUR in the oil and gas industry, and each has its advantages and limitations. Decline curve analysis (DCA) is a traditional reserves estimation technique that is widely used to estimate EUR in conventional reservoirs. However, when it comes to unconventional reservoirs, traditional methods are frequently unreliable for predicting production trends for low-permeability plays. In recent years, many approaches have been developed to accommodate the high complexity of unconventional plays and establish reliable estimates of reserves. This paper provides a methodology to predict EUR for multistage hydraulically fractured horizontal wells that outperforms many current methods, incorporates completion data, and overcomes some of the limitations of using DCA or other traditional methods to forecast production. This new approach is introduced to predict EUR for multistage hydraulically fractured horizontal wells and is presented as a workflow consisting of production history matching and forecasting using DCA combined with artificial neural network (ANN) predictive models. The developed workflow combines production history data, forecasting using DCA models and completion data to enhance EUR predictions. The predictive models use ANN techniques to predict EUR given short early production history data (3 months to 2 years). The new approach was developed and tested using actual production and completion data from 989 multistage hydraulically fractured horizontal wells from four different formations. Sixteen models were developed (four models for each formation) varying in terms of input parameters, structure, and the production history data period it requires. The developed models showed high accuracy (correlation coefficients of 0.85 to 0.99) in predicting EUR given only 3 months to 2 years of production data. The developed models use production forecasts from different DCA models along with well completion data to improve EUR predictions. Using completion parameters in predicting EUR along with the typical DCA is a major addition provided by this study. The end product of this work is a comprehensive workflow to predict EUR that can be implemented in different formations by using well completion data along with early production history data.

Download Full-text

GPU-Based Computation of Formation Pressure for Multistage Hydraulically Fractured Horizontal Wells in Tight Oil and Gas Reservoirs

Mathematical Problems in Engineering ◽

10.1155/2018/2582797 ◽

2018 ◽

Vol 2018 ◽

pp. 1-10

Author(s):

Rongwang Yin ◽

Qingyu Li ◽

Peichao Li ◽

Yang Guo ◽

Yurong An ◽

...

Keyword(s):

Oil And Gas ◽

Superposition Principle ◽

Horizontal Wells ◽

Tight Oil ◽

Formation Pressure ◽

Gas Reservoirs ◽

Integral Forms ◽

Oil And Gas Reservoirs ◽

Fractured Horizontal Wells ◽

Tight Oil And Gas

A mathematical model for multistage hydraulically fractured horizontal wells (MFHWs) in tight oil and gas reservoirs was derived by considering the variations in the permeability and porosity of tight oil and gas reservoirs that depend on formation pressure and mixed fluid properties and introducing the pseudo-pressure; analytical solutions were presented using the Newman superposition principle. The CPU-GPU asynchronous computing model was designed based on the CUDA platform, and the analytic solution was decomposed into infinite summation and integral forms for parallel computation. Implementation of this algorithm on an Intel i5 4590 CPU and NVIDIA GT 730 GPU demonstrates that computation speed increased by almost 80 times, which meets the requirement for real-time calculation of the formation pressure of MFHWs.

Download Full-text

Parametric investigation of the cyclic response of hysteretic steel dampers in braced buildings

10.21203/rs.3.rs-194100/v1 ◽

2021 ◽

Author(s):

Emanuele Gandelli ◽

Dario De Domenico ◽

Virginio Quaglini

Keyword(s):

Production Control ◽

Low Cycle Fatigue ◽

Seismic Energy ◽

Testing Procedure ◽

Design Spectrum ◽

European Code ◽

Potential Failure ◽

Number Of Cycles ◽

Design Earthquake ◽

Testing Protocols

Abstract Hysteretic steel dampers have been effectively used to improve the seismic performance of framed buildings by confining the dissipation of seismic energy into sacrifical, replaceable devices which are not part of the gravity framing system. The number of cycles sustained by the dampers during the earthquake is a primary design parameter, since it can be associated to low-cycle fatigue, with ensuing degradation of the mechanical properties and potential failure of the system. Current standards, like e.g. the European code EN 15129, indeed prescribe, for the initial qualification and the production control of hysteretic steel dampers, cyclic tests in which the devices are assessed over ten cycles with amplitude equal to the seismic design displacement dbd. This paper presents a parametric study focused on the number of effective cycles of the damper during a design earthquake in order to assess the reliability of the testing procedure proposed by the standards. The study considers typical applications of hysteretic steel dampers in low- and medium rise steel and reinforced concrete framed buildings and different ductility requirements. The results point out that the cyclic engagement of the damper is primarily affected by the fundamental period of the braced building and the design spectrum, and that, depending on these parameters, the actual number of cycles can be substantially smaller or larger that that recommended by the standards. A more refined criterion for establishing the number of cycles to be implemented in testing protocols is eventually formulated.

Download Full-text

Productivity and Drainage Area of Fractured Horizontal Wells in Tight Gas Reservoirs

SPE Reservoir Evaluation & Engineering ◽

10.2118/108110-pa ◽

2008 ◽

Vol 11 (05) ◽

pp. 902-911 ◽

Cited By ~ 77

Author(s):

Flavio Medeiros ◽

Erdal Ozkan ◽

Hossein Kazemi

Keyword(s):

Horizontal Well ◽

Oil And Gas ◽

Horizontal Wells ◽

Drainage Area ◽

Dual Porosity ◽

Hydraulic Fractures ◽

Tight Gas ◽

Natural Fractures ◽

Tight Formations ◽

Fractured Horizontal Wells

Summary This paper discusses the performance and productivity of fractured horizontal wells in heterogeneous, tight-gas formations. Production characteristics and flow regimes of unfractured and fractured horizontal wells are documented. The results show that if hydraulic fracturing affects stress distribution to create or rejuvenate natural fractures around the well, the productivity of the system is significantly increased. Unless there is significant contrast between the conductivities of the hydraulic and natural fractures, hydraulic fractures may not significantly contribute to the productivity. For extremely tight formations, the effective drainage area may be limited to the naturally fractured region around the well and the hydraulic fractures. It is also shown that very long transient flow periods govern the productivity and economics of fractured horizontal wells in tight formations. The results of this study are also applicable to oil production from fractured shale. Introduction Economic gas and oil production from low permeability reservoirs has been a challenge for the oil and gas industry. Because most of the high permeability reservoirs have been exploited and many low permeability reservoirs remain undeveloped, the latter have taken the industry attention recently. Particular attention has been given to tight-gas reservoirs with permeability in the range of micro-Darcies or below and to oil accumulation in fractured shale. Hydraulically fractured horizontal wells are the proven technology to produce oil and gas from tight formations. Hydraulic fractures reduce well drawndown, increase the productivity of horizontal wells by increasing the surface area in contact with formation, and provide high conductivity paths to the wellbore. Depending on in-situ stress orientation, hydraulic fractures can be parallel (longitudinal) or perpendicular (transverse) to horizontal well axis. Project economics in tight formations, however, depends strongly on well spacing and the number of hydraulic fractures required to drain the reservoir efficiently. Field evidence indicates that the drainage areas of fractured horizontal wells in tight formations may be limited to a rectangular region confining the horizontal well and the transverse hydraulic fractures. Also, there has been evidence that hydraulic fracturing in tight formations changes stresses in fracture drainage area, which could create or rejuvenate natural fractures in the near-vicinity of the horizontal well. This fracture network, which may be characterized as a dual-porosity system, may contribute significantly to improve productivity of the fractured horizontal well. Much work has been done (Soliman et al. 1990; Larsen and Hegre 1994; Temeng and Horne 1995; Raghavan et al. 1997; Wan and Aziz 1999; Al-Kobaisi et al. 2006) to investigate pressure-transient analysis and short- and long-term productivity of horizontal wells with single or multiple hydraulic fractures. The effect of a dual-porosity zone surrounding hydraulic fractures, however, has not been considered in the previous studies. The main objective of this study is to investigate the combined effects of a dual-porosity region and hydraulic fractures on the productivity of horizontal wells. The results presented in this work are based on a semianalytical model developed by Medeiros et al. (2006). The model was derived from the Green's function formulation of the solution for the diffusivity equation (Gringarten and Ramey, 1974, Ozkan and Raghavan, 1991a, 1991b) and has the capability to incorporate local heterogeneities. In this work, we use the semianalytical model to incorporate induced finite-conductivity fractures (transverse and longitudinal) along the horizontal well and naturally fractured zones around the hydraulically fractured horizontal well by using the dual-porosity idealization. We use the example data sets given in Tables 1 through 3 to consider different cases of horizontal wells with and without induced and natural fractures.

Download Full-text

An Analytical Solution of the Pseudosteady State Productivity Index for the Fracture Geometry Optimization of Fractured Wells

Energies ◽

10.3390/en12010176 ◽

2019 ◽

Vol 12 (1) ◽

pp. 176

Author(s):

Hui Gao ◽

Yule Hu ◽

Longchen Duan ◽

Kun Ai

Keyword(s):

Analytical Solution ◽

Flow Model ◽

Oil And Gas ◽

Geometry Optimization ◽

Horizontal Wells ◽

Productivity Index ◽

Fracture Geometry ◽

Aspect Ratios ◽

Fractured Horizontal Wells ◽

Fractured Well

The pseudosteady state productivity index is very important for evaluating the production from oil and gas wells. It is usually used as an objective function for the optimization of fractured wells. However, there is no analytical solution for it, especially when the proppant number of the fractured well is greater than 0.1. This paper extends the established fitting solution for proppant numbers less than 0.1 by introducing an explicit expression of the shape factor. It also proposes a new asymptotic solution based on the trilinear-flow model for proppant numbers greater than 0.1. The two solutions are combined to evaluate the pseudosteady state productivity index. The evaluation results are verified by the numerical method. The new solution can be directly used for fracture geometry optimization. The optimization results are consistent with those given by the unified fracture design (UFD) method. Using the analytical solution for the pseudosteady state productivity index, optimization results can be obtained for rectangular drainage areas with arbitrary aspect ratios without requiring any interpolation or extrapolation. Moreover, the new solution provides more rigorous optimization results than the UFD method, especially for fractured horizontal wells.

Download Full-text

Performance Comparison of Transversely and Longitudinally Fractured Horizontal Wells Over Varied Reservoir Permeability

SPE Journal ◽

10.2118/173331-pa ◽

2016 ◽

Vol 21 (05) ◽

pp. 1537-1553

Author(s):

Fen Yang ◽

Larry K. Britt ◽

Shari Dunn-Norman

Keyword(s):

Oil And Gas ◽

Horizontal Wells ◽

Horizontal Stress ◽

Oil Reservoirs ◽

Gas Reservoirs ◽

Lateral Direction ◽

Reservoir Permeability ◽

Actual Field ◽

Oil And Gas Reservoirs ◽

Fractured Horizontal Wells

Summary Since the late 1980s when Maersk published their work on multiple fracturing of horizontal wells in the Dan field, the use of transverse multiple-fractured horizontal wells has become the completion of choice and the “industry standard” for unconventional and tight-oil and tight-gas reservoirs. Today, approximately 60% of all wells drilled in the United States are drilled horizontally, and nearly all are multiple-fractured. However, little work has been performed to address and understand the relationship between the principal stresses and the lateral direction. This paper has as its goal to fundamentally address the questions: In which direction should I drill my lateral? Do I drill it in the direction of the maximum horizontal stress (longitudinal), or do I drill it in the direction of the minimum horizontal stress (transverse)? This work focuses on how the horizontal well's lateral direction (longitudinal or transverse fracture orientation) influences productivity, reserves, and economics of horizontal wells. Optimization studies, with a single-phase fully 3D numerical simulator including convergent non-Darcy flow, were used to highlight the importance of lateral direction as a function of reservoir permeability. The simulations, conducted for both oil and gas formations over a wide range of reservoir permeability (50 nd–5 md), compare and contrast the performance of transversely multiple-fractured horizontal wells with longitudinally fractured horizontal wells in terms of rate, recovery, and economics. This work also includes a series of field case studies to illustrate actual field comparisons of longitudinal vs. transverse horizontal well performance in both oil and gas reservoirs, and to tie these field examples to the numerical-simulation study. Further, the effects of lateral length, fracture half-length, and fracture conductivity were investigated to see how these parameters affect the decision of lateral direction in both oil and gas reservoirs. In addition, this study seeks to address how completion style (openhole or cased-hole completion) affects the selection of lateral direction. The results show the existence of a critical reservoir permeability, above which longitudinal fractured horizontal wells outperform transverse fractured horizontal wells. With openhole completions, the critical permeability is 0.04 md for gas reservoirs and 0.4 md for oil reservoirs. With cased-hole completions, longitudinal horizontal wells are preferred at a reservoir permeability above 1.5 md in gas reservoirs, and transverse horizontal wells are preferable over the entire permeability range of this study (50 nd–5 md) in oil reservoirs. These are new findings. Previous work generally suggested that longitudinal horizontal wells are a better option for gas reservoirs with permeability over 0.5 md, and for oil reservoirs with permeability over 10 md. This work extends prior study to include unconventional reservoir permeabilities. It provides critical permeability values for both gas and oil reservoirs, which are validated by the good compliance between actual field-case history and simulation results. This work also demonstrates a larger impact of completion method over fracture design. These findings could guide field operations and serve as a reference for similar studies.

Download Full-text

Cyclic engagement of hysteretic steel dampers in braced buildings: a parametric investigation

Bulletin of Earthquake Engineering ◽

10.1007/s10518-021-01156-3 ◽

2021 ◽

Author(s):

Emanuele Gandelli ◽

Dario De Domenico ◽

Virginio Quaglini

Keyword(s):

Production Control ◽

Low Cycle Fatigue ◽

Seismic Energy ◽

Testing Procedure ◽

Design Spectrum ◽

European Code ◽

Potential Failure ◽

Number Of Cycles ◽

Design Earthquake ◽

Testing Protocols

AbstractHysteretic steel dampers have been effectively used to improve the seismic performance of framed buildings by confining the dissipation of seismic energy into sacrifical, replaceable devices which are not part of the gravity framing system. The number of cycles sustained by the dampers during the earthquake is a primary design parameter, since it can be associated to low-cycle fatigue, with ensuing degradation of the mechanical properties and potential failure of the system. Current standards, like e.g. the European code EN 15129, indeed prescribe, for the initial qualification and the production control of hysteretic steel dampers, cyclic tests in which the devices are assessed over ten cycles with amplitude equal to the seismic design displacement dbd. This paper presents a parametric study focused on the number of effective cycles of the damper during a design earthquake in order to assess the reliability of the testing procedure proposed by the standards. The study considers typical applications of hysteretic steel dampers in low and medium-rise steel and reinforced concrete framed buildings and different ductility requirements. The results point out that the cyclic engagement of the damper is primarily affected by the fundamental period of the braced building and the design spectrum, and that, depending on these parameters, the actual number of cycles can be substantially smaller or larger that recommended by the standards. A more refined criterion for establishing the number of cycles to be implemented in testing protocols is eventually formulated.

Download Full-text