Utilizing Fluid and Proppant Tracer Results to Analyze Multi-Fractured Well Flow Back in Shales: A Framework for Optimizing Fracture Design and Application

King, George E.; Leonard, R. S.

doi:10.2118/140105-ms

Cited by 28 publications

(4 citation statements)

References 43 publications

(6 reference statements)

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“…We evaluated any number of fracturing stages per well from four to 20-with three hydraulic fractures created per stage by use of clustered perforations-and an even number of six to 24 closely spaced wells per drilling pad, with two parallel rows of three to 12 wells. Although there were some exceptions, data from King and Leonard (2011) showed decreased tracer recovery from the stages farther from the heel of the well, implying decreased fracturing load recovery from fracturing stages closer to the toe, and further implying decreased production from those stages. The drainage volumes for the wells were also assumed to be two rows of three to 12 wells per row in a similar arrangement, with the heels of all the wells lined up more or less below and parallel to the surface locations of the wells, with slightly more deviated drilling required to reach the heels for the wells as the well drainage areas move farther from the center of the pad.…”

Section: Example Economic Modelmentioning

confidence: 94%

Demonstration of an Efficient Concept-Selection Process for Tight and Unconventional Resources

Wehunt

Hrachovy

Ayyalasomayajula

et al. 2013

SPE Economics &Amp; Management

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Making an efficient and wise concept-selection decision-quickly selecting the right project-is often of equal or greater importance than later design and execution tasks for determining project success. An efficient assessment process is one that supports rapid assessment of an appropriately broad range of viable alternatives, leading to an optimized project design, while consuming the minimum necessary assessment resources. Value lost from a suboptimal-concept selection decision or from a needlessly prolonged assessment process is independent of value-generation opportunities during design and execution, and cannot be recovered during later project phases. The objectives of the methods shown in this paper are to improve concept-selection decision quality by allowing simultaneous optimization of interdependent development decisions, and to improve the quality of and reduce the resource requirements for simulation-derived production forecasts. This paper presents a complementary decision framework, productionforecasting process, and economic model that promote an efficient and high-quality concept-selection decision, and are particularly appropriate for early phase development concept selection and optimization for tight or unconventional resources. The method is suitable for both oil and gas resources, and is especially useful for assessing and developing large contiguous tracts.The decision framework is efficient because it is structured so that some decisions are independent of the simulation model, and those decisions can be optimized within the economic model. Our production-forecasting method is efficient because it uses small, symmetry-element reservoir-simulation models. The symmetryelement sector simulation models run fast and can evaluate many cases, but they still improve forecast quality by explicitly addressing many relevant physical effects that are not addressed by other methods that are attempting to model a much larger volume of the reservoir. The economic model is efficient because it includes an automated optimizer for those decisions that are independent of the simulation-derived forecasts, and it promotes high-quality decisions by incorporating meaningful constraints to ensure that the forecasts are both realistic and achievable. The economic model also includes a fracture efficiency factor that may be important for modeling the diminished performance observed as the number of stages increase in multifractured horizontal wells. This fracture efficiency factor may also be an important discriminator of performance between wells fractured by use of aqueous vs. nonaqueous fracturing fluids.

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Section: Example Economic Modelmentioning

confidence: 94%

Demonstration of an Efficient Concept-Selection Process for Tight and Unconventional Resources

Wehunt

Hrachovy

Ayyalasomayajula

et al. 2013

SPE Economics &Amp; Management

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“…Since fracture closure was not modeled in these simulations, almost 100% recovery of the injected tracer was observed during flowback. However, several field studies have shown very low tracer recovery [19,20,37]. The tracer retention due to fracture closure can help in understanding the low tracer recovery, which is explained in the next section.…”

Section: Normalized Tracer Concentration (C D ) =mentioning

confidence: 99%

Diagnosing Hydraulic Fracture Geometry, Complexity, and Fracture Wellbore Connectivity Using Chemical Tracer Flowback

Kumar

Sharma

2020

Energies

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The productivity of a hydraulically fractured well depends on the fracture geometry and fracture–wellbore connectivity. Unlike other fracture diagnostics techniques, flowback tracer response will be dominated only by the fractures, which are open and connected to the wellbore. Single well chemical tracer field tests have been used for hydraulic fracture diagnostics to estimate the stagewise production contribution. In this study, a chemical tracer flowback analysis is presented to estimate the fraction of the created fracture area, which is open and connected to the wellbore. A geomechanics coupled fluid flow and tracer transport model is developed to analyze the impact of (a) fracture geometry, (b) fracture propagation and closure effects, and (c) fracture complexity on the tracer response curves. Tracer injection and flowback in a complex fracture network is modeled with the help of an effective model. Multiple peaks in the tracer response curves can be explained by the closure of activated natural fractures. Low tracer recovery typically observed in field tests can be explained by tracer retention due to fracture closure. In a complex fracture network, segment length and permeability are lumped to define an effective connected fracture length, a parameter that correlates with production. Neural network-based inverse modeling is performed to estimate effective connected fracture length using tracer data. A new method to analyze chemical tracer data which includes the effect of flow and geomechanics on tracer flowback is presented. The proposed approach can help in estimating the degree of connectivity between the wellbore and created hydraulic fractures.

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“…Tracer data indicate that often in pinpoint-fracturing operations, all the stages fractured do not produce immediately or equally (King and Leonard 2011;Stegent et al 2011). It is therefore speculated that the water-composition variability represented in Fig.…”

Section: Problem Statementmentioning

confidence: 99%

Field Study of the Physical and Chemical Factors Affecting Downhole Scale Deposition in the North Dakota Bakken Formation

Cenegy

McAfee

Kalfayan

2012

SPE Production &Amp; Operations

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North Dakota Bakken oil recovery has increased nearly 100-fold over the last 5 years, driven by technological advancements in hydraulic fracturing and completion design. For one North Dakota operator with 150 Bakken producing wells, 22 of the wells have experienced at least one event of severe calcium carbonate scaling in the pump and production tubing, leading to well failure. Bakken wells are completed to a vertical depth of approximately 10,000 ft, with horizontal laterals up to 10,000 ft, and are produced by means of multizone hydraulic fracturing.The operator initially conducted a typical scale-prediction study to reduce well failures and maintain oil production. However, the scale-prediction study was challenging to perform for these Bakken wells because of the variability of the composition of the produced water. Attention then turned to the tracking and analysis of historical field conditions. A "post-mortem" of data collected from all failed wells because of scale was conducted, considering the failure type, date, type of hydraulic-fracturing procedure, pump-intake pressure, scale-inhibitor residual, calcium carbonate scaling index, geographic failure concentration, production time to failure, and cumulative water production to failure.Results showed that 82% of the wells failed during early production (defined as less than 20,000 bbls of water produced and 2 years' production since first oil), after which failures became increasingly rare. This correlated with transient alkalinity spikes in the water analyses attributed to fracturing-fluid flowback during this critical period. Simulated blending of fracturing and formation waters demonstrated that this was the most important period to maintain high scale-inhibitor residuals because of high deposition potentials.This paper discusses the various field and laboratory studies conducted in an effort to understand the problem, the results obtained, and the implications. Also discussed is the evaluation of two scale inhibitors before and after laboratory aging in simulated fracturing fluids.

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Utilizing Fluid and Proppant Tracer Results to Analyze Multi-Fractured Well Flow Back in Shales: A Framework for Optimizing Fracture Design and Application

Cited by 28 publications

References 43 publications

Demonstration of an Efficient Concept-Selection Process for Tight and Unconventional Resources

Demonstration of an Efficient Concept-Selection Process for Tight and Unconventional Resources

Diagnosing Hydraulic Fracture Geometry, Complexity, and Fracture Wellbore Connectivity Using Chemical Tracer Flowback

Field Study of the Physical and Chemical Factors Affecting Downhole Scale Deposition in the North Dakota Bakken Formation

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