What is the difference between gel-strength and yield point ?

Gel strength is something that holdscarrying  cutting when pump shut off 

ie(in static condution)but yeild point in dynamic condution

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the difference between gel-strength and yield point

Gel strength is something that holds on to for a certain period.

Yield point is when the gel strength gives way and all hell breaks loose.

Gel Strength

The gel strength is the shear stress of drilling mud that is measured at low shear rate after the drilling mud is static for a certain period of time.......

Yield Point

The Stress beyond which material becomes plastic. It is a parameter of the Bingham plastic model. Yield Point is the yield stress extrapolated to a shear rate of zero...

Is resistance of initial flow of fluid or the stress required in order to move the fluid the Yield Point (YP) is the attractive force among colloidal particles in drilling mud The YP indicates the ability of the drilling mud to carry cuttings to surface at dynamic condition Moreover, frictional pressure loss is directly related to the YP . If you have higher YP, you will have high pressure loss while the drilling mud is being circulated A unit of YP is lb/100 ft2 the difference between Yield Point and gel strength Mud Properties.gel strength .Yield Point Plastic Viscosity يعنى هى قدره سائل الحفر على رفع الرواسب (cuttings) الى السطح فى حاله وجود عمليه ( circulation) للبئر يعنى فى حاله مايكون سائل الحفر (mud) فى حاله ديناميكيه او حاله متحركه او هى المقاومه الاوليه لحركه السائل والضغط المطلوب او الجهد المطلوب لتحريك السائل من حالته الساكنه وهى المسئوله عن القوه الجاذبه فى السائل فى حالته الغرويه In oil-based mud, the causes of increasing in YP are listed below Drill solid – the more drill solid you have, the more YP will be Treatment CO2 in the mud with lime (CaO) – The lime (CaO) will chemically react with CO2 to form Calcium Carbonate (CaCO3) which will increase the YP. • Low temperature – in the oil base system, the low temperate will increase the viscosity and the YP. Please keep in mind that this is opposite to the water base system In water-based mud, the YP will be increased with following items High temperature – the high temperature environment tends to increase the YP in the water base mud. Contaminants such as carbon dioxide, salt, and anhydrite in the drilling fluids Over treatment the drilling mud with lime or caustic soda Operational impacts of the YP are as follows Equivalent Circulating Density (ECD) – The ECD typically increases when the YP increases. Hole Cleaning – When you drill a large diameter hole, the YP in the drilling mud must be high in order to help hole cleaning efficiency. In order to get the most optimized valve of PV for each a particular drilling campaign. It is very difficult to say how high of PV should be because it depends on several factors. Especially, if you are drilling in the new field, you may neek4d to start with general YP values, and then you will learn once you have experience in a particular field Gel Strength The gel strength is the shear stress of drilling mud that is measured at low shear rate after the drilling mud is static for a certain period of time. The gel strength is one of the important drilling fluid properties because it demonstrates the ability of the drilling mud to suspend drill solid and weighting material when circulation is ceased Gel Strength indicates the ability of the drilling mud to carry cuttings at static condition الخاصيه الجيليه وهى مثل مايقال اسم على مسمى حيث يكون سائل الحفر على شكل ماده جيليه متماسكه حيث تعمل هذه الخاصيه على رفع وتحميل رواسب الحفر فى حاله السكون اى فى حاله Shutdown of pumps حتى تمنع حدوث ترسب هذه الرواسب على الدقاق مما تعمل على حدوث عمليه Stuck