Drainage Area for Horizontal Wells With Pressure Drop in the Horizontal Section

2001 ◽  
Author(s):  
N.F. Saavedra ◽  
D.A. Reyes
Keyword(s):  
Pressure Drop ◽  
Horizontal Wells ◽  
Drainage Area ◽  
Horizontal Section

Experimental Research for Breakthrough Position of Horizontal Wells in Reservoirs with Bottom Water

2012 ◽  
Vol 524-527 ◽  
pp. 1232-1235 ◽  
Author(s):  
Li Feng Li ◽  
Xiang An Yue ◽  
Li Juan Zhang
Keyword(s):  
Pressure Drop ◽  
Bottom Water ◽  
Horizontal Wells ◽  
Concave Part ◽  
Entry Points ◽  
Heterogeneous Models ◽  
Two Factors ◽  
Well Trajectory ◽  
Trajectory Models ◽  
Swept Area

Finding the breakthrough position of horizontal wells is essential to water plugging and improving oil production in bottom water drive reservoirs. Physical modeling was carried out in this paper to research the law of bottom water’s movement. The experimental results indicated that: pressure drop in wells, well trajectory and area reservoir heterogeneity were all sensitive factors for breakthrough of bottom water, and the entry points of horizontal wells were determined by the combined function of them. In different well trajectory models, the concave down part of the well cooperate with pressure drop influenced the breakthrough position. Bottom water below the heel end reached the well earliest if the concave down part located at the heel end. When the concave part located at the middle of the well, the two factors played role respectively which resulted in breaking through of bottom water at two places with larger swept area. In different heterogeneous models, permeability difference and pressure drop were both favorable factors for bottom water’s non-uniformly rise. In the model that the heel end located at high permeability part, bottom water under the heel end reached the well earliest. If the heel end was set at the low permeability part, the breakthrough of bottom water occurred at the middle of the well.

Investigation of Horizontal Wells with Multi-Stage Hydraulic Fracturing Technological Efficiency in the Development of Low-Permeability Oil Reservoirs

2021 ◽  
Author(s):  
Aleksander Valerievich Miroshnichenko ◽  
Valery Alekseevich Korotovskikh ◽  
Timur Ravilevich Musabirov ◽  
Aleksei Eduardovich Fedorov ◽  
Khakim Khalilovich Suleimanov
Keyword(s):  
Hydraulic Fracturing ◽  
Performance Indicators ◽  
Oil And Gas ◽  
Horizontal Wells ◽  
Productivity Index ◽  
Specific Mass ◽  
Horizontal Section ◽  
Technological Complexity ◽  
Multi Stage ◽  
Effective Development

Abstract The deterioration of the reservoir properties of potential oil and gas bearing areas on mature and green fields, as well as the increase in the volume of hard-to-recover reserves on low-permeable reservoirs set us new challenges in searching and using effective development technologies to maintain and even increase the oil production levels. Based on successful international experience, Russian oil and gas companies use horizontal wells (HW) with multi-stage hydraulic fracturing (MSHF) for the cost-effective development of low-permeable reservoirs. Thus, since the first pilot works of drilling technologies and completion of HW with MSHF in 2011, at the beginning of 2020, over 1,200 HW with MSHF were drilled and came on stream at the fields of LLC RN-Yuganskneftegaz, about half of which are at the exploitation play AS10-12 of the northern license territory (NLT) of the Priobskoye field. In searching the best technologies and engineering solutions, the company tested different lengths of horizontal section of HW, the number of hydraulic fracturing (HF) stages and distances between hydraulic fracturing ports, as well as different specific mass of the proppant per frac port. Recently, there has been a tendency in design solutions to increase the length of the HWs and the number of hydraulic fractures with a decreasing distance between the frac ports and a decreasing specific mass of the proppant per frac port. This work studies the actual and theoretical efficiency of HW with MSHF of various designs (different lengths of horizontal section of HW and the number of HF stages) and to assess the viability of increasing the technological complexity, as well as to analyze the actual impact of loading the proppant mass per port on performing HW with MSHF. The study is based on the results of the analysis of the factual experience accumulated over the entire history of the development of the exploitation play AS10-12 of the NLT of the Priobskoye field of the Rosneft Company. In studying the viability of increasing the technological complexity, especially, increasing the length of horizontal section of HW, increasing the number of HF stages, and reducing the distance between the frac ports: we discovered the typical methodological errors made in analyzing the efficiency of wells of various designs; we developed the methodology for analysis of the actual multiplicity of indicators of wells of various designs, in particular, HW with MSHF relative to deviated wells (DW) with HF; we carried out the statistical analysis of the actual values of the multiplicity of performance indicators and completion parameters of HW with MSHF of various designs relative to the surrounding DW with HF of the exploitation play AS10-12 of the NLT of the Priobskoye field; we performed the theoretical calculation of the multiplicity of the productivity coefficient for the HW with MSHF of various designs relative to DW with HF for the standard development system of the exploitation play AS10-12 of the NLT of the Priobskoye field; we compared the actual and theoretical results. The paper also presents the results of studying the actual effect of changes of proppant's mass per port on performance indicators of HW with MSHF of the same design and with an increase in the number of fractures of the hydraulic fracturing without changing the length of horizontal section of HW. As for performance indicators, being the basis for estimating the efficiency of HW with MSHF of various designs, we used the productivity index per meter of the effective reservoir thickness and the cumulative fluid production per meter of the effective reservoir thickness per a certain period of operation. And as the completion parameters, we used the length of the horizontal section of HW, the number of HF stages, the distance between the frac ports, and the specific mass of the proppant per meter of the effective reservoir thickness per frac port. The results of this work are the determining vector of development for future design decisions in improving the efficiency of HW with MSHF.

Effects of Pressure Drop in Horizontal Wells and Optimum Well Length

SPE Journal ◽  
1999 ◽  
Vol 4 (03) ◽  
pp. 215-223 ◽  
Author(s):  
V.R. Penmatcha ◽  
Sepehr Arbabi ◽  
Khalid Aziz
Keyword(s):  
Pressure Drop ◽  
Horizontal Wells

Technological solutions for well construction in high-viscous shale hydrocarbon fields

2021 ◽  
pp. 52-62
Author(s):  
V. P. Ovchinnikov ◽  
O. V. Rozhkova ◽  
S. N. Bastrikov ◽  
D. S. Leontiev ◽  
P. V. Ovchinnikov
Keyword(s):  
High Temperature ◽  
Hydraulic Fracturing ◽  
Horizontal Wells ◽  
High Viscosity ◽  
Horizontal Section ◽  
High Temperature And Pressure ◽  
Multi Stage ◽  
Hydrocarbon Fields ◽  
Temperature And Pressure ◽  
Calcium Hydrosilicate

The article discusses the main technological processes of well construction for the production of high-viscosity hydrocarbons from productive lowporosity reservoirs with high temperature and pressure conditions, which include shale deposits of Bazhenov formation. According to the results of the review and analysis of existing solutions in the development of this deposits, the following measures were justified and proposed: construction of branched multi-hole azimuth horizontal wells, implementation of selective multi-stage hydraulic fracturing in the productive formation; the use of oil-based process fluids when opening the reservoir, the use of plugging materials for isolation of the reservoir, the hardening product of which is represented by thermally stable hydrate phases (hydrobasic hydrosilicates). Вranched wells have a long horizontal end (about 1 000 meters or more). Only a part of the horizontal section works effectively, which is the basis for the development and application of the staged, both in time and along the strike, hydraulic fracturing method. At the level of the invention, a method and apparatus for carrying out multistage selective hydraulic fracturing in wells with horizontal completion have been developed. The article describes a method for implementing multistage selective hydraulic fracturing, comparing this method with the existing ones. Much attention is given to the need to use hydrocarbon-based solutions for the initial opening the reservoir, to use cement slurries from composite materials to separate the reservoir, the hardening product of which is a stone formed by low-basic calcium hydrosilicate.

Can We Engineer Better Multistage Horizontal Completions? Evidence of the Importance of Near-wellbore Fracture Geometry from Theory, Lab and Field Experiments

2015 ◽  
Author(s):  
B.. Lecampion ◽  
J.. Desroches ◽  
X.. Weng ◽  
J.. Burghardt ◽  
J.E.. E. Brown
Keyword(s):  
Pressure Drop ◽  
Field Experiments ◽  
Horizontal Wells ◽  
Fracture Plane ◽  
Hydraulic Fractures ◽  
Multiple Fractures ◽  
Fracture Geometry ◽  
Complex Fracture ◽  
Limited Entry ◽  
The Impact

Abstract There is accepted evidence that multistage fracturing of horizontal wells in shale reservoirs results in significant production variation from perforation cluster to perforation cluster. Typically, between 30 and 40% of the clusters do not significantly contribute to production while the majority of the production comes from only 20 to 30% of the clusters. Based on numerical modeling, laboratory and field experiments, we investigate the process of simultaneously initiating and propagating several hydraulic fractures. In particular, we clarify the interplay between the impact of perforation friction and stress shadow on the stability of the propagation of multiple fractures. We show that a sufficiently large perforation pressure drop (limited entry) can counteract the stress interference between different growing fractures. We also discuss the robustness of the current design practices (cluster location, limited entry) in the presence of characterized stress heterogeneities. Laboratory experiments highlight the complexity of the fracture geometry in the near-wellbore region. Such complex fracture path results from local stress perturbations around the well and the perforations, as well as the rock fabric. The fracture complexity (i.e., the merging of multiple fractures and the reorientation towards the preferred far-field fracture plane) induces a strong nonlinear pressure drop on a scale of a few meters. Single entry field experiments in horizontal wells show that this near-wellbore effect is larger in magnitude than perforation friction and is highly variable between clusters, without being predictable. Through a combination of field measurements and modeling, we show that such variability results in a very heterogeneous slurry rate distribution; and therefore, proppant intake between clusters during a stage, even in the presence of limited entry techniques. We also note that the estimated distribution of proppant intake between clusters appears similar to published production log data. We conclude that understanding and accounting for the complex fracture geometry in the near-wellbore is an important missing link to better engineer horizontal well multistage completions.

Best Practices in DFIT Interpretation: Comparative Analysis of 62 DFITs from Nine Different Shale Plays

2022 ◽  
Author(s):  
Mark Mcclure ◽  
Garrett Fowler ◽  
Matteo Picone
Keyword(s):  
Pressure Drop ◽  
Pore Pressure ◽  
Time Pressure ◽  
Early Time ◽  
Horizontal Wells ◽  
Late Time ◽  
Fracture Length ◽  
Well Spacing ◽  
Net Pressure ◽  
The Difference

Abstract In URTeC-123-2019, a group of operators and service companies presented a step-by-step procedure for interpretation of diagnostic fracture injection tests (DFITs). The procedure has now been applied on a wide variety of data across North and South America. This paper statistically summarizes results from 62 of these DFITs, contributed by ten operators spanning nine different shale plays. URTeC-123-2019 made several novel claims, which are tested and validated in this paper. We find that: (1) a ‘compliance method’ closure signature is apparent in the significant majority of DFITs; (2) in horizontal wells, early time pressure drop due to near-wellbore/midfield tortuosity is substantial and varies greatly, from 500 to 6000+ psi; (3) in vertical wells, early-time pressure drop is far weaker; this supports the interpretation that early- time pressure drop in horizontal wells is caused by near-wellbore/midfield tortuosity from transverse fracture propagation; (4) the (not recommended) tangent method of estimating closure yields Shmin estimates that are 100-1000+ psi lower than the estimate from the (recommended) compliance method; the implied net pressure values are 2.5x higher on average and up to 5-6x higher; (5) as predicted by theory, the difference between the tangent and compliance stress and net pressure estimates increases in formations with greater difference between Shmin and pore pressure; (6) the h-function and G-function methods allow permeability to be estimated from truncated data that never reaches late-time impulse flow; comparison shows that they give results that are close to the permeability estimates from impulse linear flow; (7) false radial flow signatures occur in the significant majority of gas shale DFITs, and are rare in oil shale DFITs; (8) if false radial signatures are used to estimate permeability, they tend to overestimate permeability, often by 100x or more; (9) the holistic-method permeability correlation overestimates permeability by 10-1000x; (10) in tests that do not reach late-time impulse transients, it is reasonable to make an approximate pore pressure estimate by extrapolating the pressure from the peak in t*dP/dt using a scaling of t^(-1/2) in oil shales and t^(3/4) in gas shales. The findings have direct practical implications for operators. Accurate permeability estimates are needed for calculating effective fracture length and for optimizing well spacing and frac design. Accurate stress estimation is fundamental to hydraulic fracture design and other geomechanics applications.

scholarly journals A Numerical Model for Investigating the Steam Conformance along the Dual-String Horizontal Wells in SAGD Operations

Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3981
Author(s):  
Peng Li ◽  
Yanyu Zhang ◽  
Xiaofei Sun ◽  
Huijuan Chen ◽  
Yang Liu
Keyword(s):  
Pressure Drop ◽  
Horizontal Wells ◽  
Pressure Profile ◽  
Steam Injection ◽  
Steam Pressure ◽  
Optimization Method ◽  
Injection Time ◽  
Reservoir Model ◽  
Landing Position ◽  
Steam Chamber

Non-uniformity of the steam-assisted gravity drainage (SAGD) steam chamber significantly decreases the development of heavy oil reservoirs. In this study, to investigate the steam conformance in SAGD operations, a wellbore model is developed for fluid flow in dual-string horizontal wells. Then, a three-dimensional, three-phase reservoir model is presented. Next, the coupled wellbore and reservoir model is solved with a fully implicit finite difference method. Finally, the effects of the injector wellbore configuration, steam injection ratio and injection time on the steam conformance are investigated. The results indicate that under different injector wellbore configurations, the closer the differences between the pressure drop from the landing position of the short string to the heel of the wellbore and the pressure drop from the landing position of the short string to the toe of the wellbore, the better is the steam conformance. The smaller the difference in the steam injection rate between the long and short injection strings, the higher is the uniformity of the steam chamber. The injector annular pressure profile uniformity is consistent with the steam conformance. Creating a more uniform steam pressure in the annulus of the injector improves the uniformity of the steam chamber. The steam conformance decreases with increasing injection time, so the optimization method of steam chamber uniformity should be adjusted according to different injection times.

Two-Phase Flow Heat Transfer and Pressure Drop in Horizontal Scavenge Pipes in an Aero Engine

2014 ◽  
Author(s):  
Michael Flouros ◽  
Georgios Iatrou ◽  
Kyros Yakinthos ◽  
Francois Cottier ◽  
Markus Hirschmann
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Pressure Drop ◽  
Vertical Section ◽  
Phase Flow ◽  
Lubrication System ◽  
Two Phase ◽  
Horizontal Section ◽  
Flow Heat ◽  
Nusselt Number Correlation

In modern aero engines the lubrication system plays a key role due to the demand for high reliability. Oil is used not only for the lubrication of bearings, gears or seals, but it also removes large amounts of the generated heat. Also, air from the compressor at elevated temperature is used for sealing the bearing chambers and additional heat is introduced into the oil through radiation, conduction and convection from the surroundings. The impact of excessive heat on the oil may lead to severe engine safety and reliability problems which can range from oil coking (carbon formation) to oil fires. Coking may lead to a gradual blockage of the oil tubes and subsequently increase the internal bearing chamber pressure. As a consequence, oil may migrate through the seals into the turbo machinery and cause contamination of the cabin air or ignite and cause failure of the engine. It is therefore very important for the oil system designer to be capable to predict the system’s functionality. Coking or oil ignition may occur not only inside the bearing chamber but also in the oil pipes which carry away the air and oil mixture from the bearing chamber. Bearing chambers usually have one pipe (vent pipe) at the top of the chamber and also one pipe (scavenge pipe) at the bottom which is attached to a scavenge pump. The vent pipe enables most of the sealing air to escape thus avoid over-pressurization in the bearing compartment. In a bearing chamber sealing air is the dominant medium in terms of volume occupation and also the in terms of causing expansion phenomena. The scavenge pipe carries away most of the oil from the bearing chamber but some air is also carried away. The heat transfer in vent pipes was investigated by Busam [1], [2]. Busam has experimentally developed a Nusselt number correlation for an annular flow in a vent pipe. For the heat transfer predictions in scavenge pipes no particular Nusselt number correlation exist. This paper intends to close the gap in this area. As part of the European Union funded research programme ELUBSYS (Engine LUBrication System TechnologieS), an attempt was done to simplify the oil system’s architecture. In order to better understand the flow in scavenge pipes, high speed video was taken in two sections of the pipe (vertical and horizontal). In the vertical section the flow was a wavy annular falling film whereas the flow in the horizontal section was a an unsteady wavy stratified/slug flow. Heat transfer has been investigated in the horizontal section of the scavenge pipe, leaving the investigation on the vertical section for later. Thanks to the provided extensive instrumentation, the thermal field in, on and around the pipe was recorded, evaluated and also numerically modeled using ANSYS CFX version 14 [23]. Brand new correlations for two-phase flow heat transfer (Nusselt number) and for pressure drop (friction coefficient) in horizontal scavenge pipes are the result of this work. The Nusselt number correlation has been developed in such a way that smooth transition (i.e. no discontinuity) from two-phase into single phase flow is observed. This work was funded and conducted within the 7th EU Frame Programme for Aeronautics and Transport (AAT.2008.4.2.3).

scholarly journals Experimental Study on the Local Drag of Completion String with Packers in Horizontal Wells

Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 657 ◽  
Author(s):  
Qimin Liang ◽  
Bairu Xia ◽  
Baolin Liu ◽  
Zhen Nie ◽  
Baokui Gao
Keyword(s):  
Experimental Study ◽  
Oil And Gas ◽  
Theoretical Calculations ◽  
Horizontal Wells ◽  
Experimental Results ◽  
Economic Losses ◽  
Horizontal Section ◽  
Friction Coefficients ◽  
Oil And Gas Fields ◽  
Gas Fields

The multistage stimulation technology of horizontal wells has brought huge benefits to the development of oil and gas fields. However, the completion string with packers often encounters stuck due to the large drag in the horizontal section, causing huge economic losses. The local drag of the completion string with packers in the horizontal section is very complicated, and it has not been fully understood by theoretical calculations. A local drag experiment is designed to simulate the influence of microsteps and cuttings on the local drag of the completion string with packers in the inclined and horizontal sections. An obvious increase of the local drag of the packer is found at microsteps of the horizontal section, and the local drag is greatly affected by the amount of sand. In addition, the string with packers will vibrate during the tripping process in the deviated section, and the local drag is different when different amounts of sand are in the hole, but the change law is similar. The experimental results show that the friction coefficients of the packers with different materials in the horizontal section vary greatly, resulting in different local drags. It indicates that the local drag of the completion string not only depends on the microsteps and sand quantity in the wellbore, but also on the material difference of the packers. Only if microsteps and cuttings are removed can the completion string be tripped into horizontal wells smoothly.

The Practice and Cognition of Tracing with Drilling in Fish Bone Horizontal Well

2012 ◽  
Vol 594-597 ◽  
pp. 226-229
Author(s):  
Kai Chun Yu ◽  
Yan Zhu ◽  
Xiao Xing Li ◽  
Shi Feng Zhang
Keyword(s):  
Horizontal Well ◽  
Horizontal Wells ◽  
Fish Bone ◽  
Drilling Process ◽  
Horizontal Section ◽  
Well Production ◽  
The North ◽  
Comprehensive Exploitation ◽  
Horizontal Length ◽  
Oilfield Development

The branch well G8-33-H1Z is the first fishbone horizontal well of Daqing. The fishbone horizontal well is one type of the branch horizontal wells, which drilling again two or more branch holes in the horizontal section of the horizontal well. This well lies in G21 block where is near to the west of Daqing oilfield Changyuan area and the northeast of G20 of the north Gaotaizi oilfield. The purpose of the drilling is using branch horizontal well to control more areal reserves and increasing drainable area to improve well production. This technique can improve the economic benefit of oilfield development, which saves drilling investment, makes full use of the upper borehole to improve the comprehensive exploitation degree of the reservoir and achieves highly efficient development using less well. This well has two horizontal branches, and puts ‘trunk-branch-trunk-branch’ into effect while drilling. The first branch designed horizontal length 150m. The second branch designed horizontal length 150m. This paper introduced the tracing with drilling process of Daqing first fishbone horizontal well, and also described the complex situations and the treatment methods while drilling wellbore trajectory and constructing well and the development effect. Finally some suggestions were put forward about tracing with drilling in fishbone horizontal well.

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