Completion and Well Spacing Optimization for Horizontal Wells in Pad Development in the Vaca Muerta Shale

2016 ◽  
Author(s):  
M. Suarez ◽  
S. Pichon
Keyword(s):  
Horizontal Wells ◽  
Well Spacing ◽  
Vaca Muerta

Investigation and Optimization of the Effects of Geologic Parameters on the Performance of Gravity-Stable Surfactant Floods

SPE Journal ◽  
2016 ◽  
Vol 21 (03) ◽  
pp. 761-775 ◽  
Author(s):  
Shayan Tavassoli ◽  
Gary A. Pope ◽  
Kamy Sepehrnoori
Keyword(s):  
Salinity Gradient ◽  
Horizontal Wells ◽  
Sensitivity Study ◽  
Third Order ◽  
Fine Grid ◽  
Heterogeneous Reservoirs ◽  
Vertical Permeability ◽  
Well Spacing ◽  
Optimization Schemes ◽  
Very High

Summary A systematic simulation study of gravity-stable surfactant flooding was performed to understand the conditions under which it is practical and to optimize its performance. Different optimization schemes were introduced to minimize the effects of geologic parameters and to improve the performance and the economics of surfactant floods. The simulations were carried out by use of horizontal wells in heterogeneous reservoirs. The results show that one can perform gravity-stable surfactant floods at a reasonable velocity and with very-high sweep efficiencies for reservoirs with high vertical permeability. These simulations were carried out with a 3D fine grid and a third-order finite-difference method to accurately model fingering. A sensitivity study was conducted to investigate the effects of heterogeneity and well spacing. The simulations were performed with realistic surfactant properties on the basis of laboratory experiments. The critical velocity for a stable surfactant flood is a function of the microemulsion (ME) viscosity, and it turns out there is an optimum value that one can use to significantly increase the velocity and still be stable. One can optimize the salinity gradient to gradually change the ME viscosity. Another alternative is to inject a low-concentration polymer drive following the surfactant slug (without polymer). Polymer complicates the process and adds to its cost without a significant benefit in most gravity-stable surfactant floods, but an exception is when the reservoir is highly layered. The effect of an aquifer on gravity-stable surfactant floods was also investigated, and strategies were developed for minimizing its effect on the process.

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.

Integrated Analysis of Tracer and Pressure-Interference Tests To Identify Well Interference

SPE Journal ◽  
2020 ◽  
Vol 25 (04) ◽  
pp. 1623-1635 ◽  
Author(s):  
Ashish Kumar ◽  
Puneet Seth ◽  
Kaustubh Shrivastava ◽  
Ripudaman Manchanda ◽  
Mukul M. Sharma
Keyword(s):  
Response Times ◽  
Horizontal Wells ◽  
Integrated Approach ◽  
Pressure Response ◽  
Integrated Analysis ◽  
Well Drilling ◽  
Tracer Recovery ◽  
Well Spacing ◽  
Fractured Horizontal Wells ◽  
Interference Tests

Summary In ultralow-permeability reservoirs, communication between wells through connected fractures can be observed through tracer and pressure-interference tests. Understanding the connectivity between fractured horizontal wells in a multiwell pad is important for infill well drilling and parent-child well interactions. Interwell tracer and pressure-interference tests involve two or more fractured horizontal wells and provide information about hydraulic-fracture connectivity between the wells. In this work, we present an integrated approach based on the analysis of tracer and pressure interference data to obtain the degree of interference between fractured horizontal wells in a multiwell pad. We analyze well interference using tracer (chemical tracer and radioactive proppant tracer) and pressure data in an 11-well pad in the Permian Basin. Changes in pressure and tracer concentration in the monitor wells were used to identify and evaluate interference between the source and monitor wells. Extremely low tracer recovery and weak pressure response signify the absence of connected fractures and suggest that interference through matrix alone is insignificant. Combined tracer and pressure-interference data suggest connected fracture pathways between the communicating wells. The degree of interference can be estimated in terms of pressure response times and tracer recovery. An effective reservoir model was used to simulate pressure interference between wells during production. Simulation results indicate that well interference observed during production is primarily because of hydraulically connected fractures. Combined tracer and pressure-interference analysis provides a unique tool for understanding the time-dependent connectivity between communicating wells, which can be useful for optimizing infill well drilling, well spacing, and fracture sizing in future treatment designs.

scholarly journals Visualization Experimental Study on Well Spacing Optimization of SAGD with a Combination of Vertical and Horizontal Wells

ACS Omega ◽  
2021 ◽  
Author(s):  
Lei Tao ◽  
Lilong Xu ◽  
Xiao Yuan ◽  
Wenyang Shi ◽  
Na Zhang ◽  
...  
Keyword(s):  
Experimental Study ◽  
Horizontal Wells ◽  
Well Spacing

Closing the Gap in Characterizing the Parent Child Effect for Unconventional Reservoirs - A Case of Study in Vaca Muerta Shale Formation

2021 ◽  
Author(s):  
Alejandro Lerza ◽  
Sergio Cuervo ◽  
Sahil Malhotra
Keyword(s):  
Hydraulic Fracture ◽  
Production Performance ◽  
Drainage Area ◽  
Real Field ◽  
Well Spacing ◽  
Fracture Development ◽  
Vaca Muerta ◽  
Pressure Depletion ◽  
The Impact ◽  
Parent Child

Abstract In Shale and Tight, the term "Parent-Child effect" refers to the impact the depleted area and corresponding stress changes originated by the production of a previously drilled well, the "parent", has over the generated hydraulic fracture geometry, conforming initial drainage area and consequent production performance of a new neighbor well, called "child". Such effect might be considered analogous to the no flow boundary created when the drainage areas of two wells meet at a certain distance from them in conventional reservoirs; but, unconventional developments exhibit higher exposure to a more impactful version of this phenomena, given their characteristic tighter well spacing and the effect pressure depletion of the nearby area by the neighbor well has over the child well's hydraulic fracture development. Due to the importance the Parent-Child effect has for unconventional developments, this study aims first to generally characterize this effect and then quantify its expected specific project impact based on real field data from the Vaca Muerta formation. To do so, we developed a methodology where fracture and reservoir simulation were applied for calibrating a base model using field observed data such as microseismic, tracers, daily production data and well head pressure measurements. The calibrated model was then coupled with a geomechanical reservoir simulator and used to predict pressure and stress tensor profiles across different depletion times. On these different resulting scenarios, child wells were hydraulically fractured with varying well spacing and completion designs. Finally, the Expected Ultimate Recovery (EUR) impact versus well spacing and the parent´s production time were built for different child´s completion design alternatives, analyzed and contrasted against previously field observed data. Results obtained from the characterization work suggests the parent child effect is generated by a combination of initial drainage area changes and stress magnitude and direction changes, which are both dependent of the pressure depletion from the parent well. Furthermore, the results show how the well spacing and parent's production timing, as well as parent's and child's completion design, significantly affect the magnitude of the expected parent child effect impact over the child's EUR.

Trends in Vaca Muerta Horizontal Wells Stimulation

2017 ◽  
Author(s):  
P. E. Johanis ◽  
G. E. Triffiletti
Keyword(s):  
Horizontal Wells ◽  
Vaca Muerta

Determination of well spacing volumetric factor for assessment of final oil recovery in reservoirs developed by horizontal wells

2021 ◽  
pp. 47-53
Author(s):  
I.N. Khakimzyanov ◽  
◽  
V.Sh. Mukhametshin ◽  
R.N. Bakhtizin ◽  
R.I. Sheshdirov ◽  
...  
Keyword(s):  
Inclination Angle ◽  
Oil Recovery ◽  
Horizontal Wells ◽  
Drainage Area ◽  
Well Spacing ◽  
Volumetric Determination ◽  
Fluid Inflow

The formula for determination of volumetric factor of well spacing for assessment of final oil recovery in reservoirs developed by horizontal wells is offered. For the purpose of comparison of well spacing calculated using conventional and volumetric techniques, twelve development options of the pilot area of the Yamashinskoye field with variousplacement of vertical and horizontal wells were considered. By results of calculations, marked difference in values of well spacing was observed testifying that the conventional formula used to calculate well spacing does not consider the volume nature of fluid inflow to wells with one or more horizontal laterals. The offered technique of volumetric determination of well spacing through the inclination angle, the radius of well drainage area, and the length of a lateral considers the volumetric nature of inflow to horizontal multilateral wells.

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