Coal exploration drilling, South Kalimantan. A freshly graduated geologist, a 6/2 roster, two shifts, a lot of mud, no signal, and one very angry wasp nest.Pengeboran eksplorasi batubara di Kalimantan Selatan. Geolog baru lulus, jadwal rooster, dua shift, banyak lumpur, susah sinyal, dan satu sarang tawon yang sangat marah.
A remote area means a roster rotation (“rooster” in Indonesian mining slang). Tap a block to see how each stretch of the trip felt.Remote area berarti jadwal rooster. Tap satu blok untuk lihat rasanya tiap bagian trip.
Follow one drill hole from a dot on a coal model to a sample on the rack. (Why drill coal at all? Step 1 answers that.)Ikuti satu lubang bor dari sebuah titik di model batubara sampai jadi sample di rak. (Kenapa batubara perlu di-drilling? Dijawab di langkah 1.)
But where does that coordinate come from? Not from a guess in the field. It comes from the coal model.Tapi koordinat itu datang dari mana? Bukan tebakan di lapangan. Koordinat itu datang dari coal modelling.
A fair question. Oil is drilled to get the oil out: the well is the production. Coal is a solid and gets mined, so an exploration hole produces nothing to sell. Its product is information: a thin column of rock that shows what is buried underground, which you can’t see from the surface.Pertanyaan yang wajar. Minyak dibor untuk mengeluarkan minyaknya: sumurnya adalah produksinya. Batubara itu padat dan ditambang, jadi lubang eksplorasi tidak menghasilkan apa pun untuk dijual. Produknya adalah informasi: kolom batuan tipis yang menunjukkan apa yang terkubur di bawah tanah, yang tidak bisa dilihat dari permukaan.
What the hole tells usYang diceritakan lubang itu
More holes, more confidenceMakin banyak lubang, makin yakin
Resources are classed by confidence, and tighter drilling earns a higher class. Recommended spacing for one seam in a published Musi Banyuasin study:Sumber daya dikelompokkan menurut tingkat keyakinan, dan pemboran yang lebih rapat menghasilkan kelas yang lebih tinggi. Jarak yang direkomendasikan untuk satu seam dalam studi Musi Banyuasin:
One seam, one study. Real spacing depends on how complex each seam is.Satu seam, satu studi. Jarak sebenarnya tergantung kompleksitas tiap seam.
Next the drill pad is built, with its size and condition matched to what the rig needs. For non-portable rigs a dozer does the job. For portable rigs the pad is usually made by hand, by crew who are, let’s say, seriously strong.Berikutnya drill pad dibuat, luas dan kondisinya disesuaikan kebutuhan rig. Untuk rig non-portable pakai dozer. Untuk rig portable biasanya dikerjakan manual oleh tenaga manusia yang, bisa dibilang, sakti-sakti.
Dozers are also where my most memorable day on site started. Jump to that story.Dozer juga jadi awal hari paling berkesan di lokasi. Loncat ke ceritanya.
Once the pad is ready the rig moves in. Its layout must follow the safety rules of each site: safety lines around high-hazard zones, and PPE for every crew member.Setelah pad siap, rig dipindahkan masuk. Tata letaknya harus sesuai aturan safety tiap site: safety line di area berbahaya, dan semua kru wajib pakai APD.
For night shifts the lighting must cover the whole work area. I usually ran six 500 W floodlights around the rig, or as many as needed. And the detail that matters most: the geologist’s tent goes somewhere comfortable, in the shade and away from the engine smoke. 🙂Untuk shift malam, penerangan harus menjangkau seluruh area kerja. Saya biasanya pakai 6 lampu sorot @500 W mengelilingi rig, atau sesuai kebutuhan. Dan hal terpenting: tenda geologist harus di posisi yang enak, teduh dan jauh dari asap mesin bor. 🙂
The product is cuttings: rock fragments carried up by the fluid sprayed from the drilling tool. A Field Assistant (FA) collects the cuttings for every metre of pipe that goes in, and I describe it on the description form.Produknya adalah cutting: material batuan yang terangkut fluida yang disemprotkan dari alat bor. FA (Field Assistant) mengumpulkan cutting per meter pipa masuk, lalu saya deskripsi di form deskripsi.
The product is the core: the actual rock, pulled out as a cylinder. Keep a close eye on its progress so the coring stays accurate and the contractor doesn’t fool you. 😀Produknya adalah core: batuannya langsung, keluar berbentuk silinder. Perhatikan progresnya supaya coring tetap akurat dan tidak ditipu kontraktor. 😀
Progress is written on a board after every run. Five terms you need:Progres dicatat di papan setiap run. Lima istilah yang perlu dipahami:
Cored can’t be longer than the core run. Re-check the tape.Cored tidak mungkin lebih panjang dari core run. Cek lagi meterannya.
The core is described, then sampled as needed. Coal quality and geotech samples are handled very differently.Core dideskripsi lalu disampling sesuai kebutuhan. Sample kualitas batubara dan sample geotek diperlakukan sangat berbeda.
The coal core is separated into six parts. Each part is wrapped in plastic wrap to keep it airtight, then bagged with its sample number and depth. The goal: proximate and ultimate analysis, and what the results say about the coal.Core batubara dipisahkan jadi enam bagian. Tiap bagian dilapisi plastic wrap supaya kedap udara, lalu dimasukkan ke plastik berisi nomor sample dan kedalamannya. Tujuannya: analisis proksimat dan ultimat serta hubungannya dengan batubaranya.
Geotech samples get special treatment and their own description sheet. They’re taken every 5–7 m per lithology, and the core must be intact: no broken or damaged core gets sampled.Sample geotek perlakuannya lebih khusus dan lembar deskripsinya berbeda. Diambil tiap 5–7 m per litologi, dan core tidak boleh patah atau rusak.
Then write down the sample number, the depth, and which end is top and which is bottom.Lalu catat nomor sample, kedalaman, serta posisi top dan bottom.
When the hole reaches its target, and before the pipe is pulled, we log it. This gives the accurate depth of the coal, which is later reconciled against the sample depths.Setelah pengeboran mencapai target, sebelum pipa diangkat, dilakukan logging. Hasilnya kedalaman batubara yang akurat, yang nanti direkonsiliasi dengan data kedalaman sample.
Logging parameters are set according to need; on this job we only ran density and gamma.Parameter logging disesuaikan kebutuhan; di pekerjaan ini hanya memakai densitas dan gamma.
Logging done? Time to move. Pack up, move to the next point, and start again from the stake out.Logging selesai? Saatnya moving. Beres-beres, jalan ke titik berikutnya, lalu mulai lagi dari stake out.
We worked two shifts, morning and night. Flip between them.Kami kerja dua shift, pagi dan malam. Coba bolak-balik.
Daylight meant seeing the whole site, and the geologist’s tent had to sit in the shade, away from the rig’s engine smoke.Siang hari kami bisa melihat seluruh area, dan tenda geologist harus di tempat teduh, jauh dari asap mesin bor.
At night, the lighting had to cover the entire work area. Six 500 W floodlights around the rig were my usual setup. Drilling, pipe handling and description all carried on.Malam hari, penerangan harus menjangkau seluruh area kerja. Enam lampu sorot 500 W mengelilingi rig adalah setup saya. Pemboran, angkat pipa, dan deskripsi tetap jalan.
Mobile signal was hard to come by. To call or message home, we first had to drive somewhere that had some.Sinyal susah. Untuk telepon atau kirim kabar ke rumah, kami harus naik mobil dulu cari tempat yang ada sinyalnya.
What the table looked like depended on where the hole was:Seperti apa meja makannya tergantung di mana lubang bornya:
For a city person, the first trip felt like a year. In my free time I tried to read, for one reason: I didn’t want to stay stuck out here, so I had to keep learning. 😄Buat orang kota, trip pertama rasanya seperti setahun. Waktu senggang saya usahakan baca buku, dengan satu alasan: saya nggak mau terjebak di sini, jadi harus belajar biar pintar. 😄
In between, card games with the drivers and the drilling crew.Selang-seling, main kartu sama driver dan kru drilling.
From the outside it looks like geology. From the inside, a big part of it was logistics, and we managed that too: the food, the exploration equipment, and the inventory of drilling samples.Dari luar kelihatannya geologi. Dari dalam, sebagian besarnya logistik, dan itu juga kami kelola: makanan, perlengkapan eksplorasi, dan inventory sample drilling.
Meals are company-paid, but the arrangement changes with the location: mess hall at a mining camp, a flying camp, or catering from local residents.Makan ditanggung perusahaan, tapi pengaturannya berubah tiap lokasi: mess hall camp tambang, flying camp, atau catering warga.
Everything the cycle above needs has to be on site, at every pad. Examples from the steps above:Semua yang dibutuhkan siklus di atas harus ada di lokasi, di setiap pad. Contoh dari langkah-langkah di atas:
Every sample is a physical item that has to be wrapped, labelled, tracked and traced back to a depth. Lose the label, lose the data.Setiap sample adalah barang fisik yang harus dibungkus, diberi label, dilacak, dan bisa ditelusuri ke kedalamannya. Label hilang, data hilang.
Seven short scenes. Tap next.Tujuh adegan singkat. Tap next.
“The present is the key to the past.”The principle of uniformitarianism (James Hutton, popularised by Charles Lyell). The phrase itself is usually credited to Archibald Geikie, 1905.“Masa kini adalah kunci masa lalu.”Prinsip uniformitarianisme (James Hutton, dipopulerkan Charles Lyell). Frasanya sendiri umumnya dikaitkan dengan Archibald Geikie, 1905.
Every core we pulled out was a page of Earth’s history, and we read it by knowing how the world works today. That was my first job: long days, strange hours, good company, and stories I’m still telling.Setiap core yang kami angkat adalah selembar sejarah bumi, dan kami membacanya dengan memahami cara kerja bumi hari ini. Begitulah kerja pertama saya: hari yang panjang, jam yang aneh, teman-teman yang seru, dan cerita yang masih saya ceritakan sampai sekarang.