Frac Hit Induced Production Losses: Evaluating Root Causes, Damage Location, Possible Prevention Methods and Success of Remediation Treatments, Part II

Abstract

Millions of dollars in production losses are occurring from fracture-driven well-to-well interference (frac hits) in horizontal wells in unconventional play reservoirs. The work presented in SPE 187192 has been continued in this paper with a new case study (Case Study V), data from a pair of Wolfcamp B wells in the Permian Basin. The parent well suffered fracture interference during the child well's stimulation operations, negatively effecting production. The child and parent wells were both completed with the "plug and perf" technique. The parent well was completed with 74 stages while the child well's completion consisted of 105 frac stages. The child well was drilled with a longer lateral and the first 72 stages of the well's fracturing operations caused clear, repeatable pressure changes in the parent well. The data from these two wells is rich in cause and effect and permits compelling observations and conclusions. These findings were then compared to those from Case Studies I-IV, SPE 187192. Detailed plots of the pressure changes superimposed with fracturing data were created and studied to better understand the significance and cause of what was happening to the Case Study V parent well. The shut-in pressure data from the parent well was taken at the intake of the electrical submersible pump (ESP) and recorded in 1-3 minute increments. Both wells have the same number of perf clusters per stage, stage spacing and amount of sand per stage. One-second fracture stimulation data for both completions was available. Case Study V plots and examples from Case Studies I-IV were put side-to-side and back-to-back to quickly view the similarities and differences. Fact-based conclusions were reached regarding causality of fracture-driven communication and interference between these wells. Preface The study for this paper is based on and uses data from nearly 200 individual fracture stimulation stages pumped in five pairs of wells. In order to document and discuss that much information, there are numerous plots and illustrations. While this is perhaps unconventional, it must be pointed out that a paper that is focused on data MUST show the data. Time constraints prevented the inclusion of several additional plots and "Part III" is being planned and is in the works. SPE 187192 (part I), King et al (2017) will be referred to several times and a few of the old plots are shown. There are new plots and observations from Case Studies I-IV.

Multi-Fracture Propagation Considering Perforation Erosion with Respect to Multi-Stage Fracturing in Shale Reservoirs

“…According to optical fiber diagnosis, Ugueto C. et al [14] found that the efficiency of perforation clusters was only 50~70%. The studies mentioned above suggest that fractures are not propagated uniformly in multi-stage fracturing, which is not conducive to reservoir stimulation [15,16].…”

Effects of parent well spacing on the poroelastic behaviors in the infill zone in shale oil reservoirs: A case study in Jimsar Shale Oil, China

“…Field observations indicate that the hydraulic fracturing quality and performance of wells in the infill zone can be largely influenced by previously placed parent wells. Negative impacts on the fracturing quality and production in infill zones have been reported in the major shale plays in North America 12,13 . In addition to the impact on well production, the impact of parent well depletion on infill zones can be proved by fracture hits, pressure oscillation, DAS and DTS data, and microseismic data 14,15 .…”

“…Negative impacts on the fracturing quality and production in infill zones have been reported in the major shale plays in North America. 12,13 In addition to the impact on well production, the impact of parent well depletion on infill zones can be proved by fracture hits, pressure oscillation, DAS and DTS data, and microseismic data. 14,15 The drilling and completion of horizontal wells in infill zones can also cause well control problems in parent wells as the infill well fractures connect to pre-existing fracture networks and the fracturing fluids and proppants enter the parent wells.…”