Most oil and gas wellbores are drilled using water based mud (WBM), but this is the case when drilling through non-reactive formations that does not contain swelling shale. In reactive shale formation, KCl Polymer additive should be added to the mud. It will provide a source of potassium ions which will help stabilizing the reactive shale. So that the swelling process is minimized. The basis of the KCL polymer mud system is the polymer used as a wrapper for rock pieces during borehole cleaning process. In the wells in the POK Field, the use of polymer KCL mud is evaluated on trajectories of 17½", 12¼", and 8½ ". The evaluation process uses parameters that aim to find the suitable mud properties that result in the best drilling performance in each trajectory in the POK Field well. The determination of the best drilling performance is based on drilling time. The parameters used in this research are: rate of penetration, trip time, yield point (YP), K+ content, mud weight (MW), viscosity (m), plastic viscosity (PV), and gel strength (GS), mud cake, pH, and additional parameter (excess cement). Based on analysis and investigation, the best drilling performance for trajectory of 17½" occured in POK 1075 well, while the best performance for the trajectories 12¼” and 8½” occured in POK 1058 well. Therefore the KCl polymer mud properties used in these wells can be used as a reference and basis for planning mud systems for the next wells.

Salah satu metode dalam Enhanced Oil Recovery adalah Chemicalflooding. Pada penelitian laboratorium ini dilakukan injeksi larutan surfaktan berbahan dasar AOS pada batuan sandstone dengan konsentrasi 05%, 1%, dan 2% dalam masing-masing salinitas 5.000 ppm dan 10.000 ppm. Hal ini bertujuan untuk mengetahui pengaruh kenaikan konsentrasi pada surfaktan terhadap perolehan minyak. Sebelum dilakukan tahapan injeksi, terlebih dahulu dilakukan uji fisik larutan surfaktan, sehingga dapat ditentukan larutan yang akan diinjeksikan ke dalam batuan. Dari proses uji fisik didapati bahwa semakin tinggi konsentrasi larutan makan nilai dari densitas, viskositas, dan spesific gravity akan turut meningkat. Dalam prakteknya, larutan surfaktan akan menurunkan nilai tegangan antarmuka (IFT) sehingga dapat meningkatkan perolehan minyak yang tersisa dalam pori-pori batuan. Nilai IFT terendah adalah pada surfaktan dengan konsentrasi 2%, sedangkan yang tertinggi surfaktan dengan konsentrasi 0,5%. Pengaruh kenaikan konsentrasi surfaktan terbukti lebih optimal, memiliki nilai recovery factor sebesar 43,89% dengan konsentrasi 2% salinitas 10.000 ppm.

Enhanced Oil Recovery (EOR) is an effort to increase oil recovery after primary recovery and secondary recovery. One method used is chemical injection using surfactants. Sodium Lignosulfonate (SLS) is one of the anionic surfactants commonly used in the EOR process. Sodium Lignosulfonate can be made by bagasse synthesis, as an alternative to the use of lignosulfonate surfactant. The purpose of this study was to determine the effect of the middle phase emulsion and interfacial tension on the recovery factor results. The method used is the core injection. The injection fluid used is Sodium Lignosulfonate surfactant which has been tested for its characteristics. This research uses core flood devices and synthesized Berea cores. Core injection is carried out in several variations of salinity and surfactant concentration. The results of the study show that the largest recovery result is at 1.5% 15000 ppm with a recovery factor of 5.34% where the emulsions are the least among other compositions but the emulsions are stable at 48 hours and the IFT value is also relatively low at 4.34 mN/m. The lowest recovery results are at 1.5% 4000 ppm with a recovery factor of 3.24% where the emulsions are highest but the emulsions are stable at 336 hours, and the IFT value is relatively high at 10.40 mN / m. Based on this study it can be concluded that if the middle phase emulsion is quickly stable and the IFT value is low it will result in enhanced oil recovery.

Indonesia is one of the largest sugarcane producing countries in the world. At present, the use of bagasse is only as compost, electricity generation, etc. In the oil industry, bagasse can use as a base material in making surfactants that function as fluid reservoir oil injection to improve oil recovery factors, so it is good to develop a type of plant-based local surfactant with a lot of raw materials in Indonesia. The purpose of this study was to see that bagasse can increase the oil recovery factor at low salinity. The methods used is a laboratory study using a concentration of 1%; 1.5%; 2%; 2.5% and 3% NaLS and salinity of 4000 ppm, 5000 ppm, and 15000 ppm NaCl. The Surfactant first conducted a compatibility test then core flooding was carried out to obtain the recovery factor value. The results obtained were surfactants with variations of 1.5% 4000 ppm; 1.0% 15000 ppm; and 1.5% 15000 ppm which passes the compatibility test with the recovery factor value sequentially is 3.24%; 3.62%; and 5.34%. It shows that NaLS surfactant can increase the oil recovery factor at low salinity by 5.34% by optimizing 1.5% NaLS 15000 ppm concentration.

<p class="NoSpacing1"><em>Surfactant flooding may increase oil recovery by lowering interfacial tension between oil and water. Bagasse is one of the organic materials which contain fairly high lignin, where lignin is the basic substance of making Natrium Lignosulfonate (NaLS) Surfactant. In this research, bagasse based surfactant was applied for surfactant flooding. The research was divided into two sections, namely: phase behavior test and NaLS Surfactant flooding where the water contained 70,000 ppm NaCl. Two surfactant concentrations which were used were 0.75% and 1.5% NaLS surfactant. Phase behavior tests were carried out to find the middle phase emulsion formation. Based on phase behavior test results, the percentage of emulsion volume for 0.75% and 1.5% NaLS is 13.75% and 8.75%, respectively. NaLS surfactant flooding was performed for to obtain the best recovery factor. FTIR equipment used determine recovery factor. The optimum condition was obtained at 0.75% NaLS surfactant concentration where the recovery factor was 4.4%.</em><em></em></p>