This paper investigates the effect of variable perforation configurations on proppant transport, settling, and distribution across different perforation clusters in multistage horizontal wells. The results are compared to other previously published data (Ahmad and Miskimins, 2019) using different proppant sizes and densities. A 30-foot horizontal laboratory apparatus with three perforation clusters is used to simulate a multistage horizontal well. Low viscosity fresh water is used as the carrier fluid to transport the proppant. This research incorporates the influence of testing various injection rates and proppant concentrations on proppant transport of 100-mesh brown sand. Different perforation configurations are used to test the perforation effect on proppant transport using similar injection rates and proppant concentrations. A 200-gallon tank is used to mix the proppant before injecting the slurry mixture using a slurry pump. The apparatus also incorporates a variable frequency drive, a flow meter and pressure transducers. Sieve analysis is then conducted to identify the proppant distribution exiting from each cluster at different perforation configurations. It commonly assumed that the injected proppant is distributed evenly across the perforation clusters and that the distribution of fluid and proppant is identical. However, this research shows that this is not always the case. The results show uneven fluid and proppant distributions between clusters when altering the perforation configurations, injection rates, and proppant concentrations. Sieve analysis also shows different size distribution of the settled and exited sand through different clusters and individual perforations. Such information is beneficial to understanding transport in horizontal, multi-stage completions and how such impacts the overall treatment efficiency.

Summary Proppant transport in horizontal wellbores has received significant industry focus over the past decade. One of the most challenging tasks in the hydraulic fracturing of a horizontal well is to predict the proppant concentration that enters each perforation cluster within the same stage. The main objective of this research is to investigate the effect of different perforation configurations on proppant transport, settling, and distribution across different perforation clusters in multistage horizontal wells. To simulate a fracturing stage in a horizontal wellbore, a laboratory-based 30-ft horizontal clear apparatus with three perforation clusters is used. Fresh water (~1 cp) is used as the carrier fluid to transport the proppant. This research incorporates the effect of testing three different injection rates each at four different proppant concentrations on proppant transport. Different perforation configurations are also used to test the perforation effect on proppant transport using similar injection rates and proppant concentrations for the tested 100-mesh proppant. The proppant is mixed with fresh water in a 200-gallon tank for at least 10 minutes to ensure the consistency of the slurry mixture. The mixture is then injected into the transparent horizontal wellbore through a slurry pump. This laboratory apparatus also includes a variable frequency drive, a flowmeter, and two pressure transducers located right before the first two perforation clusters. Sieve analysis is conducted to understand the ability of fresh water to carry bigger particles of the mixture at different injection rates, proppant concentrations, and perforation configurations. The results show different fluid and proppant distributions occur when altering the perforation configurations, injection rates, and proppant concentrations. The effect of gravity is extreme when using a limited-entry configuration at each cluster [1 shots/ft (SPF)] located at the bottom of the pipe, especially at low injection rates, resulting in uneven proppant distribution with a heal-biased distribution. However, even proppant distribution is observed by changing the limited entry perforation configuration to the top of the horizontal pipe at similar injection rates and low proppant concentration. Increasing the proppant concentration reduces the void spaces between the particles and pushes them away toward the toe cluster. Even proppant distribution is also observed across the three perforation clusters when using higher flow rates and a 2 SPF perforation configuration located at both the top and the bottom of the pipe. The results show uneven fluid and proppant distributions between clusters with a toe-biased distribution when altering the perforation configurations to 3 and 4 SPF. The results of the sieve analyses show different size distributions of the settled and exited proppant through different perforations and clusters. This illustrates the ability of fresh water to transport different percentages of various proppant sizes to different perforations and clusters within a single stage. Frequently, the injected proppant is assumed to be distributed evenly across the perforation clusters and the distribution of fluid and proppant is assumed to be identical. This research provides a better understanding of the proppant transport inside the multiclusters in a horizontal wellbore by using fresh water as the carrier fluid. This research is unique in that it experimentally studies the effect of changing the perforation configurations and orientation on the proppant transport and distribution. This study comprehensively investigates the effect of injection parameters that influence the proppant transport behavior such as injection rate and proppant concentrations. The work shows that the distribution of the transported proppant is different across individual clusters and varies between different perforations within each cluster. Such information is beneficial to understanding transport in horizontal, multistage completions and how such impacts the overall treatment efficiency, especially when employing limited-entry perforation techniques.

In multistage, multicluster treatments, distributing the proppant evenly among the multiple perforation clusters is considered one of the key challenges. Uneven proppant distribution in multiple clusters can significantly affect fracture conductivity, which in turn severely affects the well's productivity. Dimensional analysis using the Buckingham π-theorem was utilized to develop the experimental correlations using the experimental data. The laboratory tests data of 100 mesh brown and 40/70 mesh white sands (SG of 2.65) at various proppant concentrations, injection rates, and with various perforation configurations were combined and used to develop the correlation. This paper offers a newly developed experimental correlation for the proppant distribution that may be utilized to forecast the distribution of proppant between various clusters in the multistage, multicluster stimulation. Such correlations are essential to be considered in future hydraulic fracturing treatment designs, as they offer insightful information and aid in optimizing the projected proppant distribution across several perforation clusters within a single hydraulic fracturing stage. Thus, the multistage, multicluster horizontal wellbore achieves uniform proppant distribution between the various perforation clusters.

Proppant transport in horizontal wellbores has received significant industry focus over the past decade. One of the most challenging tasks in the hydraulic fracturing of a horizontal well is to predict the proppant concentration that enters each perforation cluster within the same stage. The main objective of this research is to investigate the effect of different limited-entry perforation configurations on proppant transport, settling, and distribution across different perforation clusters in multistage horizontal wells. To simulate a fracturing stage in a horizontal wellbore, a laboratory-based 30-foot horizontal clear apparatus with three perforation clusters is used. Fresh water (~1 cp) is utilized as the carrier fluid to transport the proppant. This research incorporates the effect of testing three different injection rates each at four different proppant concentrations on proppant transport. Different limited-entry perforation configurations are also used to test the perforation effect on proppant transport using similar injection rates and proppant concentrations for the same proppant size. The proppant is mixed with fresh water in a 200-gallon tank for at least 10 minutes to ensure the consistency of the slurry mixture. The mixture is then injected into the transparent horizontal wellbore through a slurry pump. This laboratory apparatus also includes a variable frequency drive, a flow meter, and two pressure transducers located right before the first two perforation clusters. Sieve analysis is conducted to understand the ability of fresh water to carry bigger particles of the mixture at different injection rates, proppant concentrations, and perforation configurations. The results show different fluid and proppant distributions occur when altering the perforation configurations, injection rates, and proppant concentrations. The effect of gravity is extreme when using a limited entry configuration at each cluster (1 SPF) located at the bottom of the pipe, especially at low injection rates, resulting in uneven proppant distribution with a heal-biased distribution. However, even proppant distribution is observed by changing the limited entry perforation configuration to the top of the horizontal pipe at similar injection rates and low proppant concentration. Increasing the proppant concentration reduces the void spaces between the particles and pushes them away toward the toe cluster. Even proppant distribution is also observed across the three perforation clusters when using high flow rates and a 2 SPF perforation configuration located at both the top and the bottom of the pipe. The results of the sieve analyses show different size distributions of the settled and exited proppant through different perforations and clusters. This illustrates the ability of fresh water to transport different percentages of different proppant sizes to different perforations and clusters within a single stage. Frequently, the injected proppant is assumed to be distributed evenly across the perforation clusters and that the distribution of fluid and proppant is identical. However, this research adds data to the portfolio that this assumption is generally not valid. Additionally, the distribution of the transported proppant is observed to be different across individual clusters and different perforations within each cluster. Such information is beneficial to understanding transport in horizontal, multi-stage completions and how such impacts the overall treatment efficiency, especially when employing limited-entry perforation techniques.