Lack of inhibiting effect of oil emplacement on quartz cementation: Evidence from Cambrian reservoir sandstones, Paleozoic Baltic Basin

Abstract

Currently, the question of whether or not the presence of oil in sandstone inhibits quartz cementation and preserves porosity is still debated. Data from a number of Cambrian sandstone oil fi elds and dry fi elds have been studied to determine the effects of oil emplacement on quartz cementation. The data show that the porosity distribution is not affected by the presence of oil in sandstones from oil fi elds and dry fi elds with similar porosity distribution. From this, it can be concluded that oil emplacement does not lead to preservation of primary porosity, and silica supply for quartz cementation is derived from internal sources. Rather, in spite of large variation in porosity and quartz cement content, a regular pattern of porosity decrease is related to increasing temperature or depth. The observed heterogeneity is due to local factors that infl uence the precipitation of quartz cement, including sandstone architecture, i.e., distribution of shales within the sandstone bodies, and sandstone thickness. Heterogeneity is inherent to sandstone architecture and to the fact that silica for quartz cementation is derived from heterogeneously distributed local pressure solution. Models predicting reservoir properties should encompass facies and architecture as important independent factors.

Exceptional reservoir quality in HPHT reservoir settings: Examples from the Skagerrak Formation of the Heron Cluster, North Sea, UK

“…However, other studies (e.g Aase and Walderhaug, 2005;Molenaar et al, 2008;Saigal et al, 1992) have suggested that there is no correlation between hydrocarbon emplacement and porosity preservation.…”

The Effect of Oil Saturation On the Mechanism of Compaction In Granular Materials: Higher Oil Saturations Lead To More Grain Fracturing and Less Pressure Solution

“…Pressure solution is understood to be a major cause of loss of porosity and permeability in many reservoirs because it causes compaction and cementation (Weyl 1959;McBride 1989;Murphy et al The effect of oil emplacement on pressure solution and the ensuing quartz cementation remains a controversial topic. Previous attempts to understand the effect of oil emplacement on quartz cementation and pressure solution, mainly from field-based studies, have not been conclusive (Ramm 1992;Emery et al 1993;Walderhaug 1994;Marchand et al 2002;Aase and Walderhaug 2005;Molenaar et al 2008). Over the past few decades, two end-member conceptual models have evolved regarding the effect of oil emplacement on pressure solution and diagenesis.…”

“…Nedkvitne et al (1993) and Midtbo et al (2000) suggested that quartz and authigenic clay cements can precipitate even at high oil saturations. Moreover, lack of variation in quartz cement volumes between oil and water legs in some oil fields led to an interpretation that oil emplacement can have no inhibiting effect on quartz cementation and pressure solution (Ramm 1992;Ramm and Bjørlykke 1994;Aase and Walderhaug 2005;Molenaar et al 2008). Taylor et al (2010) incorporated petrographic data and numerical modeling studies using proprietary software to study Jurassic North Sea Fulmar Formation sandstones to conclude that the presence of hydrocarbon pore fluids has no significant influence in quartz cementation and in preservation of reservoir quality.…”

Chlorite meniscus cement – implications for diagenetic mineral growth after oil emplacement

“…There has been intense debate for some years on quartz cementation and the possible inhibition of quartz cementation and other diagenesis by the emplacement of oil (Dixon et al, 1989;Emery et al, 1993;Gluyas et al, 1993;Boles and Hickey, 1997;Worden et al, 1998;Marchand et al, 2000Marchand et al, , 2001Marchand et al, , 2002Worden and Morad, 2000;Haszeldine et al, 2003;Molenaar et al, 2008). This is an important issue as if true that oil does inhibit diagenesis, it would mean that many of the present porous and permeable sandstone reservoirs are mainly caused by migration and accumulation of oil (e.g.…”

“…At present, the question is not solved with several studies arguing for external supply and ceasing of diagenesis when oil has been emplaced (Dixon et al, 1989;Emery et al, 1993;Gluyas et al, 1993;Boles and Hickey, 1997). Others have put forward arguments and numerical data pointing to little if any effect of oil on diagenesis (Ramm, 1992;Nedkvitne et al, 1993;Ramm and Bjørlykke, 1994;Midtbø et al, 2000;Aase and Walderhaug, 2005), and in some of the earliest literature on diagenesis was already suggested by Lowry (1956) and Rittenhouse (1971) that diffusion in water film might cause continued cementation in oilfilled reservoirs (see further discussion by Molenaar et al, 2008).…”