Is There Really Anything New in PSD?

Abstract Accurate formation sand particle size distribution (PSD) is critical for sand control design. Many in the oil industry have explored various aspects of PSD determination and the methods used for analysis. This paper aims to establish a set of best practices for generating PSD data from core samples. The analysis of PSDs of core material is an important first step in determining sand control design and must be carefully conducted. Historically, PSDs have been measured by one or both methods of either Sieve Analysis or Laser Particle Size Analysis (LPSA). Both methods should theoretically yield the same results, however, the results can frequently differ. By addressing common shortcomings in sample selection and preparation, and by evaluating the capabilities of both sieve analysis and LPSA, this work provides clear guidance for confidently conducting representative and reliable PSD measurements. PSD measurements were conducted using both sieve analysis and LPSA techniques on cores sourced from the same field over a range of permeabilities. An effort was made during the process to preserve as much core as possible during the initial analysis so that the remaining core could be utilized again if needed. Careful handling protocols were established at this time to ensure consistent results within the laboratory setting. Dry sieve PSD's were compared to LPSA PSD's for the same core samples and observations are provided which help to understand strengths and limitations of each method. Additionally, API Standard Sieve Analysis was compared to sieve analysis PSD's calculated from mid-point values between two sieves. Both the API Standard Sieve Analysis and the mid-point sieve calculation PSD were then compared to LPSA for the same rock samples. The literature has reported that sub 325 mesh fines can be electrostatically held above sieve screens that have larger openings. Both quantitative and qualitative analysis of the particles retained above the 325 mesh screen in the sieve analysis provided evidence that sub 325 fines were retained above the 325 mesh screen and counted in the weight of particles larger than the 325 mesh. This study highlights key limitations of both techniques. The data demonstrates that when proper core sampling and preparation protocols are followed, LPSA offers a more comprehensive and functionally relevant PSD profile. However, in cases where LPSA is not available, careful handling of the core material as well as the data can lead to a reasonable result if utilizing sieve analysis. While extensive industry literature exists on both LPSA and Sieve analysis techniques, this paper introduces a novel comparative approach that has not been previously documented.