Changes

|+ {{table number|1}}Rock-fluid potential problems, prevention, and corrective action

|+ {{table number|1}}Rock-fluid potential problems, prevention, and corrective action

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! Potential Problem

! Potential Problem || Contributing Minerals || Damaging Fluids and System || Damage Prevention || Damage Correction

! Contributing Minerals

! Damaging Fluids and System

! Damage Prevention

! Damage Correction

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| Clay swelling (water sensitive)

| Clay swelling (water sensitive) || Smectite lllite-Smectite Chlorite-Smectite lllite Kaolinite || Fluids and System Freshwater-based fluids Any water with inadequate concentration of cations || Oil-based mud Potassium Ammonium chloride Calcium chloride || Preflush with HCl and NH₄ CI HCI/HF acidize Postflush with NH₄ CI and clay stabilizer

| Smectite lllite-Smectite Chlorite-Smectite lllite Kaolinite

| Fluids and System Freshwater-based fluids Any water with inadequate concentration of cations

| Oil-based mud Potassium Ammonium chloride Calcium chloride

| Preflush with HCl and NH₄ CI HCI/HF acidize Postflush with NH₄ CI and clay stabilizer

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| Fines movement (rate sensitive)

| Fines movement (rate sensitive) || Kaolinite lllite Chlorite lllite-smectite Chlorite-smectite Clay size particles of quartz or other minerals || High transient pressure High flow rates || Perforate slightly under-balanced (1000 psi) Increase well rate slowly Maximize perforations per ft Select rate less than critical velocity Use clay stabilizer || Preflush if needed with HCl and NH₄ CI Acidize with HCI/HF Postflush with NH₄ CI and clay stabilizer

| Kaolinite lllite Chlorite lllite-smectite Chlorite-smectite Clay size particles of quartz or other minerals

| High transient pressure High flow rates

| Perforate slightly under-balanced (1000 psi) Increase well rate slowly Maximize perforations per ft Select rate less than critical velocity Use clay stabilizer

| Preflush if needed with HCl and NH₄ CI Acidize with HCI/HF Postflush with NH₄ CI and clay stabilizer

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