TY - THES

T1 - Avoidance of permeability reduction of sand control installations caused by fines and sand invasion from poorly consolidated sandstone formations

AU - Trummer, Sebastian

N1 - embargoed until 08-02-2017

PY - 2016

Y1 - 2016

N2 - This thesis compares and evaluates the potential of chemical systems to improve the sand and fines retention in poorly consolidated sandstone formations. Furthermore, it is evaluated if excellent sorting and sphericity of the gravel pack material will improve sand and fines retention and positively influence the performance of gravel packing systems. Commercially available chemical systems, which are used to either, coat the gravel pack material or sand grains of the formation, are evaluated for their efficiency and practical value in well operations. These chemicals are claimed to improve the retention of finer particle sizes by sand control installations or to consolidate the near wellbore formation, avoiding that finer particles reach the gravel pack (GP). As a consequence, sand and fines should not invade the GP installation and therefore not reduce the pore space and finally the conductivity of the filter material. It is expected that the chemical in-situ consolidation systems will slightly reduce the permeability of the formation. The application and efficiency of the chemical systems is tested in a laboratory setup. As an alternative or addition to chemical means to improve the sand and fines retention of GP installations, glass beads filter material with near-perfect sphericity and better sorting, which demonstrated equal pack permeability as common proppants at lower median grain diameters, are evaluated. The results obtained by the laboratory tests indicate, that these new filter materials are indeed suitable for gravel pack installations since they provide slightly improved sand and fines retention. Furthermore, successful results could be obtained by resin coating of the gravel pack filter material, whereas the combination of resin coating and new filter materials showed the best results. Artificial scaling as an in-situ consolidation mechanism proved to be successful as well. Other methods, such as consolidation by polymers or nano-particle coating of the gravel pack material showed insufficient results and were not able to stop the sand and fines invasion. The application of in-situ consolidation of the formation by an acrylic resin on the other hand was able to stop sand and fines migration but resulted in the complete loss of formation permeability.

AB - This thesis compares and evaluates the potential of chemical systems to improve the sand and fines retention in poorly consolidated sandstone formations. Furthermore, it is evaluated if excellent sorting and sphericity of the gravel pack material will improve sand and fines retention and positively influence the performance of gravel packing systems. Commercially available chemical systems, which are used to either, coat the gravel pack material or sand grains of the formation, are evaluated for their efficiency and practical value in well operations. These chemicals are claimed to improve the retention of finer particle sizes by sand control installations or to consolidate the near wellbore formation, avoiding that finer particles reach the gravel pack (GP). As a consequence, sand and fines should not invade the GP installation and therefore not reduce the pore space and finally the conductivity of the filter material. It is expected that the chemical in-situ consolidation systems will slightly reduce the permeability of the formation. The application and efficiency of the chemical systems is tested in a laboratory setup. As an alternative or addition to chemical means to improve the sand and fines retention of GP installations, glass beads filter material with near-perfect sphericity and better sorting, which demonstrated equal pack permeability as common proppants at lower median grain diameters, are evaluated. The results obtained by the laboratory tests indicate, that these new filter materials are indeed suitable for gravel pack installations since they provide slightly improved sand and fines retention. Furthermore, successful results could be obtained by resin coating of the gravel pack filter material, whereas the combination of resin coating and new filter materials showed the best results. Artificial scaling as an in-situ consolidation mechanism proved to be successful as well. Other methods, such as consolidation by polymers or nano-particle coating of the gravel pack material showed insufficient results and were not able to stop the sand and fines invasion. The application of in-situ consolidation of the formation by an acrylic resin on the other hand was able to stop sand and fines migration but resulted in the complete loss of formation permeability.

KW - Sandkontrolle

KW - Sandinvasion

KW - Feinteilinvasion

KW - Gravel Packs

KW - unkonsolidierte Formationen

KW - Sand Control

KW - Gravel Pack

KW - Unconsolidated Formations

KW - Fines Invasion

M3 - Master's Thesis

ER -