Abstract

During fracturing, a nearby offset monitor well often observes a pressure response as hydraulic fractures propagate from the stimulated well towards the monitor well. This response is known as a frac hit or FDI (frac driven interaction). Frac hit data is collected and characterized in each newly stimulated PAD.

The objective is to evaluate the frac hit information to understand the hydraulic fracture and parent-child effect. This paper discusses some hypotheses about the response of frac hit response relates to the geomechanical properties.

A workflow to analyze the frac hits is proposed. Each FDI is characterized with 3 parameters: time of delay, intensity, and magnitude. The workflow was applied to horizontal oil wells (∼40 °API) in an analogous zone in the Vaca Muerta.

The database (8000 samples) was used to compare the behavior of the frac hits depending on the landing zone, distance, depletion, etc. The workflow is a statistical analysis that used the intensity, magnitude, and time of delay to understand the connectivity and propose mitigations.

Another analysis identified which variable had the strongest correlation with the loss of productivity and measured the degree of interaction between the child and parent depending on the fracture design. A new variable called maximum intensity was calculated per well.

Finally, all learnings will support decision making by having readily available data to improve the understanding of optimal well spacing and completion design in development fields, while considering cost tredoffs.

Introduction

The data sample consisted of 61 PADs, 254 parent wells affected by hydraulic fracturing stimulation from 207 black oil child wells in wells which were navigated in different landing zones: Shallow Upper, Upper and Lower. The fracture design of child and parent wells have a range of fluid intensity (20-90 bbl/ft) and proppant intensity (1400-3500 lb/ft). These wells were grouped into three different fields with geological and geomechanical similarities. No stress anomalies are observed within the data set. The frac hit data is shown on the map below (Figure 1).

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