Abstract: Techniques for determining a rock wettability alteration include circulating a first brine fluid into a test cell that includes a rock sample and a hydrocarbon fluid disposed on a surface of the rock sample, the first brine fluid having a property at a first value; contacting the rock sample and the hydrocarbon fluid with the first brine fluid; measuring a first contact angle between the rock sample and the hydrocarbon fluid in contact with the first brine fluid; at least partially displacing the first brine fluid with a second brine fluid in the test cell, the second brine fluid having the property at a second value; contacting the rock sample and the hydrocarbon fluid with the second brine fluid; measuring a second contact angle between the rock sample and the hydrocarbon fluid in contact with the second brine fluid; and determining a wettability alteration of the rock sample based on at least one of the measured first or second contact angles.

Abstract: Techniques for determining a rock wettability alteration include circulating a first brine fluid into a test cell that includes a rock sample and a hydrocarbon fluid disposed on a surface of the rock sample, the first brine fluid having a property at a first value; contacting the rock sample and the hydrocarbon fluid with the first brine fluid; measuring a first contact angle between the rock sample and the hydrocarbon fluid in contact with the first brine fluid; at least partially displacing the first brine fluid with a second brine fluid in the test cell, the second brine fluid having the property at a second value; contacting the rock sample and the hydrocarbon fluid with the second brine fluid; measuring a second contact angle between the rock sample and the hydrocarbon fluid in contact with the second brine fluid; and determining a wettability alteration of the rock sample based on at least one of the measured first or second contact angles.

Abstract: Techniques for determining a rock wettability alteration include circulating a first brine fluid into a test cell that includes a rock sample and a hydrocarbon fluid disposed on a surface of the rock sample, the first brine fluid having a property at a first value; contacting the rock sample and the hydrocarbon fluid with the first brine fluid; measuring a first contact angle between the rock sample and the hydrocarbon fluid in contact with the first brine fluid; at least partially displacing the first brine fluid with a second brine fluid in the test cell, the second brine fluid having the property at a second value; contacting the rock sample and the hydrocarbon fluid with the second brine fluid; measuring a second contact angle between the rock sample and the hydrocarbon fluid in contact with the second brine fluid; and determining a wettability alteration of the rock sample based on at least one of the measured first or second contact angles.

Abstract: A contact angle measurement system includes a housing, a rock sample holder positioned within the housing, a fluid dropper attached to the housing, and a sonicator attached to the housing. The holder can support a rock sample whose contact angle is to be measured. The fluid dropper is positioned relative to the holder to drop a fluid droplet on the rock sample when the rock sample is supported by the holder. The housing can transmit the sound wave to the fluid droplet on the rock sample, and the sound wave can sonically remove the fluid droplet from the rock sample.

Abstract: A contact angle measurement system includes a housing, a rock sample holder positioned within the housing, a fluid dropper attached to the housing, and a sonicator attached to the housing. The holder can support a rock sample whose contact angle is to be measured. The fluid dropper is positioned relative to the holder to drop a fluid droplet on the rock sample when the rock sample is supported by the holder. The housing can transmit the sound wave to the fluid droplet on the rock sample, and the sound wave can sonically remove the fluid droplet from the rock sample.

Abstract: Techniques for determining a rock wettability alteration include circulating a first brine fluid into a test cell that includes a rock sample and a hydrocarbon fluid disposed on a surface of the rock sample, the first brine fluid having a property at a first value; contacting the rock sample and the hydrocarbon fluid with the first brine fluid; measuring a first contact angle between the rock sample and the hydrocarbon fluid in contact with the first brine fluid; at least partially displacing the first brine fluid with a second brine fluid in the test cell, the second brine fluid having the property at a second value; contacting the rock sample and the hydrocarbon fluid with the second brine fluid; measuring a second contact angle between the rock sample and the hydrocarbon fluid in contact with the second brine fluid; and determining a wettability alteration of the rock sample based on at least one of the measured first or second contact angles.