Predicting of the Geometrical Behavior of Formations in Subsurface Based on the Analysis of LWD/MWD Data While Drilling Horizontal Wells

2021 ◽  
Author(s):  
Serhii Petrovych Tyvonchuk
Keyword(s):  
Horizontal Well ◽  
Oil And Gas ◽  
Horizontal Wells ◽  
High Accuracy ◽  
Entry Point ◽  
Donets Basin ◽  
Data Set ◽  
Bedding Angle ◽  
Entry Points ◽  
Vertical Thickness

Abstract The successful penetration of oil and gas formations by a horizontal well depends on the accuracy of the forecast of the depth and angle of the layers’ dip at the entry point. Methods and mathematical algorithms for predicting the geometric behavior of formations during drilling of a horizontal well at the stage of its approach to the entry point into target productive horizons are developed. The relationship between the formation dip, their stratigraphic thickness, and apparent vertical thickness in vertical and sub-horizontal wells is considered. It is shown that even small angles of inclination can lead to a significant influence on the prediction of the point of formation opening by a horizontal well. A detailed correlation of the offset well section with a horizontal well one while drilling was used for the analysis. A method for predicting the depth of disclose of the target formation by a horizontal well based on the change in the apparent vertical thickness is shown. A mathematical algorithm for calculating the apparent bedding angle on the basis of initial and while drilling data has been obtained. The calculated bedding angle allows predicting the depth of the target formation penetration with a horizontal well. The proposed method for predicting the horizontal well landing point depth allows avoiding errors associated with non-horizontal layering. The use of the proposed technique when drilling a number of horizontal wells in the oil fields of the Dnieper-Donets Basin (DDB) and the Pre-Carpathian Foredeep made it possible to determine with high accuracy the apparent bedding angle, even at their small values. The calculations made it possible to predict the depth of entry into the target formation during drilling with high accuracy. This is especially important in the context of small oil deposits, where it is impossible to make significant adjustments to the lateral position of the horizontal part of the wellbore. The predicted depths of the entry points into the formations were confirmed by the drilling results. The use of the proposed method makes it possible to perform high-quality geosteering while drilling horizontal wells at the stage of approaching the target formation entry point using the minimum data set. The simplicity of the method allows you to quickly analyze the geological section penetrated by a horizontal well and determine its geometric behavior. This approach makes it possible to successfully open pay formations with horizontal wells even without using a pilot well.

The Effect of Well Azimuth or Don't Let Your Landman Plan Your Well Path!

2015 ◽  
Author(s):  
Fen Yang ◽  
Larry K. Britt ◽  
Shari Dunn-Norman
Keyword(s):  
Horizontal Well ◽  
Oil And Gas ◽  
Horizontal Wells ◽  
Horizontal Stress ◽  
Well Performance ◽  
Gas Reservoirs ◽  
Principal Stresses ◽  
Lateral Direction ◽  
Well Completion ◽  
Stimulation Of

Abstract Since the late 1980's 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 become the “industry standard” for unconventional and tight oil and tight gas reservoirs. Today approximately sixty percent of all wells drilled in the United States are drilled horizontally and nearly all of them are multiple fractured. Because a horizontal well adds additional cost and complexity to the drilling, completion, and stimulation of the well we need to fully understand anything that affects the cost and complexity. In other words, we need to understand the affects of the principal stresses, both direction and magnitude, on the drilling completion, and stimulation of these wells. However, little work has been done to address and understand the relationship between the principal stresses and the lateral direction. This paper has as its goal to fundamentally address the question, in what 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)? The answer to this question relates directly back to the title of this paper and please "Don't let your land man drive that decision." This paper focuses on the horizontal well's lateral direction (longitudinal or transverse fracture orientation) and how that direction influences productivity, reserves, and economics of horizontal wells. Optimization studies using a single phase fully three dimensional numeric simulator including convergent non-Darcy flow were used to highlight the importance of lateral direction as a function of reservoir permeability. These studies, conducted for both oil and gas, are used to identify the point on the permeability continuum where longitudinal wells outperform transverse wells. The simulations compare and contrast the transverse multiple fractured horizontal well to longitudinal wells based on the number of fractures and stages. Further, the effects of lateral length, fracture half-length, and fracture conductivity were investigated to see how these parameters affected the decision over lateral direction in both oil and gas reservoirs. Additionally, how does completion style affect the lateral direction? That is, how does an open hole completion compare to a cased hole completion and should the type of completion affect the decision on in what direction the lateral should be drilled? These simulation results will be used to discuss the various horizontal well completion and stimulation metrics (rate, recovery, and economics) and how the choice of metrics affects the choice of lateral direction. This paper will also show a series of field case studies to illustrate actual field comparisons in both oil and gas reservoirs of longitudinal versus transverse horizontal wells and tie these field examples and results to the numeric simulation study. This work benefits the petroleum industry by: Establishing well performance and economic based criteria as a function of permeability for drilling longitudinal or transverse horizontal wells,Integrating the reservoir objectives and geomechanic limitations into a horizontal well completion and stimulation strategy,Developing well performance and economic objectives for horizontal well direction (transverse versus longitudinal) and highlighting the incremental benefits of various completion and stimulation strategies.

Geomechanical analysis of horizontal wells in terms of stability for drilling — A case study from the Peri-Baltic Syneclise

2021 ◽  
Vol 40 (11) ◽  
pp. 805-814
Author(s):  
Michał Kępiński ◽  
Pramit Basu ◽  
David Wiprut ◽  
Marek Koprianiuk
Keyword(s):  
Horizontal Well ◽  
Oil And Gas ◽  
Horizontal Wells ◽  
Microseismic Monitoring ◽  
Earth Model ◽  
Gas Field ◽  
Horizontal Section ◽  
Stress Regime ◽  
Geomechanical Analysis

This paper presents a shale gas field geomechanics case study in the Peri-Baltic Syneclise (northern Poland). Polish Oil and Gas Company drilled a vertical well, W-1, and stimulated the Silurian target. Next, a horizontal well, W-2H, drilled the Ordovician target and partially collapsed. The remaining interval was stimulated, and microseismic monitoring was performed. A second horizontal well, W-3H, was drilled at the same azimuth as W-2H, but the well collapsed in the upper horizontal section (Silurian). A geomechanical earth model was constructed that matches the drilling experiences and well failure observations found in wells W-1, W-2H, and W-3H. The field was found to be in a strike-slip faulting stress regime, heavily fractured, with weak bedding contributing to the observed drilling problems. An analysis of safe mud weights, optimal casing setting depths, and optimal drilling directions was carried out for a planned well, W-4H. Specific recommendations are made to further enhance the model in any future studies. These recommendations include data acquisition and best practices for the planned well.

Design of Horizontal Wellbore in Dadas Shales of Turkey by Considering Wellbore Stability and Reservoir Geomechanics

2021 ◽  
Author(s):  
Sukru Merey ◽  
Can Polat ◽  
Tuna Eren
Keyword(s):  
Hydraulic Fracturing ◽  
Horizontal Well ◽  
Oil And Gas ◽  
Horizontal Wells ◽  
Horizontal Stress ◽  
Wellbore Stability ◽  
Horizontal Drilling ◽  
Horizontal Wellbore ◽  
Reservoir Geomechanics ◽  
Maximum Horizontal Stress

Abstract Currently, many horizontal wells are being drilled in Dadas shales of Turkey. Dadas shales have both oil (mostly) and gas potentials. Thus, hydraulic fracturing operations are being held to mobilize hydrocarbons. Up to 1000 m length horizontal wells are drilled for this purpose. However, there is not any study analyzing wellbore stability and reservoir geomechanics in the conditions of Dadas shales. In this study, the directions of horizontal wells, wellbore stability and reservoir geomechanics of Dadas shales were designed by using well log data. In this study, the python code developed by using Kirsch equations was developed. With this python code, it is possible to estimate unconfined compressive strength in along wellbore at different deviations. By analyzing caliper log, density and porosity logs of Dadas shales, vertical stress of Dadas shales was estimated and stress polygon for these shale was prepared in this study. Then, optimum direction of horizontal well was suggested to avoid any wellbore stability problems. According to the results of this study, high stresses are seen in horizontal directions. In this study, it was found that the maximum horizontal stress in almost the direction of North-South. The results of this study revealed that direction of maximum horizontal stress and horizontal well direction fluid affect the wellbore stability significantly. Thus, in this study, better horizontal well design was made for Dadas shales. Currently, Dadas shales are popular in Turkey because of its oil and gas potential so horizontal drilling and hydraulic fracturing operations are being held. However, in literature, there is no study about horizontal wellbore designs for Dadas shales. This study will be novel and provide information about the horizontal drilling design of Dadas shales.

Evaluation of Horizontal Well Performance After Drilling-Induced Formation Damage

2005 ◽  
Vol 127 (3) ◽  
pp. 257-263 ◽  
Author(s):  
Y. Ding ◽  
G. Renard
Keyword(s):  
Horizontal Well ◽  
Oil And Gas ◽  
Horizontal Wells ◽  
Integrated Approach ◽  
Formation Damage ◽  
Well Performance ◽  
Wellbore Modeling ◽  
Open Hole ◽  
Testing Techniques ◽  
Study Laboratory

It is well recognized that near-wellbore formation damage can dramatically reduce well productivities, especially for open hole completed horizontal wells. The economic impact of poor productivity of these wells has pushed toward significant efforts in recent years to study laboratory testing techniques and numerical modeling methods for predicting and controlling drilling-induced formation damage. This paper presents an integrated approach, combining a near-wellbore modeling with laboratory experiments for data acquisition as input for the model, to evaluate the performance of oil and gas wells after drilling-induced formation damage.

scholarly journals Study on a New Transient Productivity Model of Horizontal Well Coupled with Seepage and Wellbore Flow

Processes ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 2257
Author(s):  
Peng Liu ◽  
Qinghua Wang ◽  
Yanli Luo ◽  
Zhiguo He ◽  
Wei Luo
Keyword(s):  
Real Time ◽  
Horizontal Well ◽  
Single Phase ◽  
Oil And Gas ◽  
Horizontal Wells ◽  
Digital Transformation ◽  
Two Phase ◽  
Transient Model ◽  
Wellbore Flow ◽  
Oil Gas

Digital transformation has become one of the major themes of the development of the global oil industry today. With the development of digital transformation, on-site production will surely achieve further automated management, that is, on-site production data automatic collection, real-time tracking, diagnosis and optimization, and remote control of on-site automatic adjustment devices. In this process, the realization of real-time optimization work based on massive data collection needs to be carried out combined with oil and gas well transient simulation. Therefore, research of the horizontal well capacity prediction transient model is one of the important basic works in the work of oil and gas digital transformation. In this paper, the method and process of establihing the transient calculation model of single-phase flow in horizontal wells are introduced in detail from three aspects: reservoir seepage, horizontal wellbore flow (taking one kind of flow as an example), and the coupling model of two flows. The model is more reliable through the verification of pressure recovery data from multiple field logs. The transient model of single-phase seepage in horizontal wells will lay the foundation for the establishment of transient models of oil-gas two-phase seepage and oil-gas-water three-phase seepage.

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

2008 ◽  
Vol 11 (05) ◽  
pp. 902-911 ◽  
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.

Using DNA-Logging to Determine Inflow Profile in Horizontal Wells

2021 ◽  
Author(s):  
Arsenii Stanislavovich Posdyshev ◽  
Pavel Vladimirovich Shelyakin ◽  
Nurislam Maratovich Shaikhutdinov ◽  
Aleksey Alekseevich Popov ◽  
Maria Dmitrievna Logacheva ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Horizontal Well ◽  
Oil And Gas ◽  
Saturation Temperature ◽  
Horizontal Wells ◽  
Field Studies ◽  
Sequencing Data ◽  
Gas Field ◽  
Field Development ◽  
Inflow Profile

Abstract The purpose of this work is to adapt and apply Next Generation Sequencing methods in oil and gas well field studies. Relatively recent NGS methods provide a description of a geological formation by analyzing millions of DNA sequences and represent an entirely new way to obtain information about oil and gas reservoirs and the composition of their fluids, which could significantly change the approach to exploration and field development. We present the results of pilot work to determine the inflow profile in a horizontal well based on DNA markers. The technology is based on the comparison of bacterial DNA from drill cuttings obtained while drilling with DNA from microorganisms of fluids obtained during production at the wellhead. Because of their high selectivity, individual microbes live only under certain conditions (salinity, oil saturation, temperature) and can be used as unique natural biomarkers. The comparison of DNA samples of drilling cutting and produced fluid allows for identification of the segment of the horizontal well from which the main flow comes, as well as identifying the type of incoming fluid (water, oil, gas) without stopping the operation process and without conducting expensive downhole operations. As a result of these studies, the microbial communities of the oil-bearing sands and formation fluids of the Cretaceous deposits (group BS) in Western Siberia were identified, and the relative numerical ratio of microorganisms in the formations was determined. It was shown that the microbiome diversity changes with depth, and depends on the lithological composition, and sequencing data obtained from cuttings samples correlate with data from wellhead samples of produced fluid. Thus, the practical applicability of DNA sequencing for solving field problems in oil and gas field development, in particular for determining the inflow profile in horizontal wells, was confirmed.

Immiserizing Growth

2019 ◽  
Keyword(s):  
Political Economy ◽  
Secondary Data ◽  
Household Survey ◽  
Data Set ◽  
Republic Of China ◽  
The Poor ◽  
Poverty Measures ◽  
Entry Points ◽  
Country Analysis ◽  
Cross Country

Immiserizing Growth occurs when growth fails to benefit, or harms, those at the bottom. It is not a new concept, appearing such figures as Malthus, Ricardo and Marx. It is also not empirically insignificant, occurring in between 10% and 35% of cases, depending on the data set and the growth and poverty measures used. In spite of this, it has not received its due attention in the academic literature, dominated by the prevailing narrative that ‘growth is good for the poor’. The chapters in this volume aim to arrive at a better understanding of when, why and how growth fails the poor. They combine discussion of mechanisms of Immiserizing Growth with empirical data on trends in growth, poverty and related welfare indicators. In terms of mechanisms, politics and political economy are chosen as useful entry points to explain IG episodes. The disciplinary focus is diverse, drawing on economics, political economy, applied social anthropology, and development studies. A number of methodological approaches are represented including statistical analysis of household survey and cross-country data, detailed ethnographic work and case study analysis drawing on secondary data. Geographical coverage is wide including Bolivia, the Dominican Republic, Ecuador, India, Indonesia, Mexico, Nigeria, the People’s Republic of China, Singapore, and South Korea, in addition to cross-country analysis. As the first book-length treatment of Immiserizing Growth in the literature, we believe that this volume constitutes an important step in redirecting attention to this issue.

scholarly journals 2D–3D reconstruction of distal forearm bone from actual X-ray images of the wrist using convolutional neural networks

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ryoya Shiode ◽  
Mototaka Kabashima ◽  
Yuta Hiasa ◽  
Kunihiro Oka ◽  
Tsuyoshi Murase ◽  
...  
Keyword(s):  
Wrist Joint ◽  
High Accuracy ◽  
Training Data ◽  
Small Data ◽  
Data Set ◽  
Accuracy Estimation ◽  
X Ray ◽  
Learning Network ◽  
Forearm Bone ◽  
Deep Learning Network

AbstractThe purpose of the study was to develop a deep learning network for estimating and constructing highly accurate 3D bone models directly from actual X-ray images and to verify its accuracy. The data used were 173 computed tomography (CT) images and 105 actual X-ray images of a healthy wrist joint. To compensate for the small size of the dataset, digitally reconstructed radiography (DRR) images generated from CT were used as training data instead of actual X-ray images. The DRR-like images were generated from actual X-ray images in the test and adapted to the network, and high-accuracy estimation of a 3D bone model from a small data set was possible. The 3D shape of the radius and ulna were estimated from actual X-ray images with accuracies of 1.05 ± 0.36 and 1.45 ± 0.41 mm, respectively.

scholarly journals Stereoelectroencephalography

Neurosurgery ◽  
2012 ◽  
Vol 72 (3) ◽  
pp. 353-366 ◽  
Author(s):  
Francesco Cardinale ◽  
Massimo Cossu ◽  
Laura Castana ◽  
Giuseppe Casaceli ◽  
Marco Paolo Schiariti ◽  
...  
Keyword(s):  
Interquartile Range ◽  
Entry Point ◽  
Target Point ◽  
Epileptogenic Zone ◽  
Localization Error ◽  
Drug Resistant ◽  
Robot Assisted ◽  
Data Set ◽  
Essential Information

Abstract BACKGROUND: Stereoelectroencephalography (SEEG) methodology, originally developed by Talairach and Bancaud, is progressively gaining popularity for the presurgical invasive evaluation of drug-resistant epilepsies. OBJECTIVE: To describe recent SEEG methodological implementations carried out in our center, to evaluate safety, and to analyze in vivo application accuracy in a consecutive series of 500 procedures with a total of 6496 implanted electrodes. METHODS: Four hundred nineteen procedures were performed with the traditional 2-step surgical workflow, which was modified for the subsequent 81 procedures. The new workflow entailed acquisition of brain 3-dimensional angiography and magnetic resonance imaging in frameless and markerless conditions, advanced multimodal planning, and robot-assisted implantation. Quantitative analysis for in vivo entry point and target point localization error was performed on a sub-data set of 118 procedures (1567 electrodes). RESULTS: The methodology allowed successful implantation in all cases. Major complication rate was 12 of 500 (2.4%), including 1 death for indirect morbidity. Median entry point localization error was 1.43 mm (interquartile range, 0.91-2.21 mm) with the traditional workflow and 0.78 mm (interquartile range, 0.49-1.08 mm) with the new one (P < 2.2 × 10−16). Median target point localization errors were 2.69 mm (interquartile range, 1.89-3.67 mm) and 1.77 mm (interquartile range, 1.25-2.51 mm; P < 2.2 × 10−16), respectively. CONCLUSION: SEEG is a safe and accurate procedure for the invasive assessment of the epileptogenic zone. Traditional Talairach methodology, implemented by multimodal planning and robot-assisted surgery, allows direct electrical recording from superficial and deep-seated brain structures, providing essential information in the most complex cases of drug-resistant epilepsy.

Sign in / Sign up

Export Citation Format

Share Document