Oil based packer fluids

An oleaginous fluid comprising a homogeneous mixture of:

• (a) a liquid oleaginous medium selected from the group consisting of light lubricating oil fractions, heavy naphtha having a boiling range between about 300.degree. to 600.degree. F., crude petroleum oil from which the light ends have been removed, still bottoms and diesel oil from the crude distillation of crude petroleum oil and mixtures thereof;
• (b) an organophilic clay comprising the reaction product of
• an organic onium compound selected from the group consisting of acidic salts of primary, secondary and tertiary amines and organic quarternary ammonium compounds;
• said organic onium compound containing at least one organic radical having at least 10 carbon atoms selected from the group consisting of alkyl, alkylene and alkylidene, and
• a smectite clay selected from the group consisting of montmorillonite, hectorite and saponite;
• (c) a polar dispersant for said clay selected from the group consisting of water, and low molecular weight alcohols, ketones, diketones, nitroalkanes, alkene carbonates, ether alcohols, ether esters, and mixtures thereof;
• and
• (d) a polyfunctional amino silane represented by the formula:
• NH.sub.2 --Y--Si(OR.sub.6).sub.3
• wherein Y is an alkylene radical containing from 2 to 8 carbon atoms and R.sub.6 is an alkyl radical containing from 1 to 5 carbon atoms in an amount sufficient to raise the yield temperature of said organophilic clay in said fluid.

An oil base packer fluid comprising a homogeneous mixture of

• (a) diesel oil;
• (b) from 10 lbs. per 42 gallon barrel to 40 lbs. per 42 gallon barrel of the total fluid of an organophilic clay selected from the group consisting of dimethyldioctadecyl ammonium bentonite, dimethylbenzyloctadecyl ammonium bentonite, cocoamine bentonite and mixtures thereof;
• (c) a clay dispersant comprising from 2% to 20% by volume of the total volume of liquid in said fluid of water;
• and
• (d) at least 0.5% by volume of the total volume of liquid in said fluid of gamma aminopropyltriethoxy silane.

In a method of producing an oil base packer fluid and transferring said fluid to a desired location within a wellbore, wherein said fluid comprises a mixture of a liquid oleaginous medium, an effective gelling amount of an organophilic clay comprising the reaction product of an organic onium compound and a smectite clay, and a dispersant for said organophilic clay in an effective dispersing amount, the improvement comprising:

• (a) adding to said fluid a polyfunctional amino silane represented by the formula:
• ##STR8## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are each selected from the group consisting of hydrogen, alkyl, aryl, cycloalkyl, and alkylaryl;
• and X is selected from the group consisting of alkylene, arylene, alkarylene, arylalkylene, cycloalkylene, aminoalkylene, aminoarylene, aminoalkylarylene, aminoarylalkylene and aminocycloalkylene in an amount sufficient to raise the yield temperature of said organophilic clay in said fluid;
• (b) placing said fluid at the desired location within said wellbore;
• and
• (c) raising the temperature of said fluid above said yield temperature of said organophilic clay to cause said fluid to gel.