SPE 135607 A Comprehensive Workflow for Early Analysis and Interpretation of Flowback Data From Wells in Tight Gas/Shale Reservoir Systems D. Ilk, Texas A&M University/DeGolyer and MacNaughton; S.M. Currie, Texas A&M University/Devon Energy Corp.; D. Symmons, Consultant; J.A. Rushing, Anadarko Petroleum Corp.; N.J. Broussard, El Paso Corporation; and T.A. Blasingame, Texas A&M University Copyright 2010, Society of Petroleum Engineers This paper was prepared for presentation at the SPE Annual Technical Conference and Exhibition held in Florence, Italy, 19–22 September 2010. This paper was selected for presentation by an SPE program committee following review of information contained in an abstract submitted by the author(s). Contents of the paper have not been reviewed by the Society of Petroleum Engineers and are subject to correction by the author(s). The material does not necessarily reflect any position of the Society of Petroleum Engineers, its officers, or members. Electronic reproduction, distribution, or storage of any part of this paper without the written consent of the Society of Petroleum Engineers is prohibited. Permission to reproduce in print is restricted to an abstract of not more than 300 words; illustrations may not be copied. The abstract must contain conspicuous acknowledgment of SPE copyright. Abstract Flowback data are defined as the early time-pressure-rate (TPR) data which are taken immediately following the completion and stimulation of a given well. Although typically discounted or even ignored, this data has a wealth of well/reservoir information. Analysis can provide forward-looking indications of long-term well deliverability as well as an early diagnosis of any potential production problems. Effective analysis of early TPR data, however, requires the utilization of all data sources and data types — for example: phase rates, pressures, choke settings, sand production, chlorides content, etc. The purpose of this paper is to provide a comprehensive workflow for early-time flowback data which provides a unique visualization of these data, as well as a correlative and integrated analysis of these data (i.e., comparing different data types and functions, correlating one data type with another, etc.). The major steps in a generic "flowback" workflow include: ● Collection and quality control of TPR and other well performance/completion data. ● Construction/calibration of a base well/reservoir model (including well completion and stimulation parameters). ● Construction/application of specialized plots to identify features in the data at a very basic level (i.e., water unloading). ● Correlation of flowback data using empirical and non-parametric models. ● Extrapolation of parametric and non-parametric models to provide predictive estimates of early-time well performance. ● Implementation of an assessment loop to guide future production/completion practices. The proposed methodology is demonstrated using case studies of wells completed in tight/shale gas reservoir systems. Extensive discussion is provided for the analysis/interpretation of flowback data; as well as our efforts to identify and quantify factors which affect and control production. The approach used in this work is that of a "dashboard" of (static) diagnostic plots as well as correlations/plots for multiple-well sets of flowback data. While the focus of this workflow is the diagnostic analysis of flowback data, we also provide guidance towards the use of flowback and long-term well performance data in "model-based" analyses. Introduction The concept of "flowback" is quite old — historically many (if not most) wells were "managed" during early production as to not damage the reservoir or the wellbore tubulars. In very recent times the focus on tight gas/shale gas resources has lead to extremely large (and expensive) well stimulation treatments (often one-half of the well cost), and as such, the process of bringing a well onto production has attained something of an art form — a balance of trying to maximize initial performance, but also to begin production carefully, so as not to damage the well and/or impair long-term production. In this paper we focus on the analysis/interpretation of the process of flowback, not the objectives or the potential ramifications of poor flowback practices. In particular, our model-based analyses may provide an assessment of damage, but we do not pursue quantification of geomechanical effects (e.g., pressure-dependent permeability or proppant embedment), nor do we propose specific flowback design procedures, although we do provide some "holistic" guidelines, designed to ensure that the data obtained from a flowback procedure is relevant and can be analyzed/interpreted.